US 191, SR 87 & SR 264 corridor study

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ARIZONA DEPARTMENT OF TRANSPORTATION
J. Fife Symington
Governor
Charles E. Cowan
Director
Harry A. Reed
Transportation Planning Division
STATE TRANSPORTATION BOARD
Larry Chavez
Chainnan
Verne Seidel
Vice Chainnan
Members
Donald Denton
Hank Gietz
Sharon Megdal
Linda Brock Nelson
James Soto
22
u.s. 191, S.R. 87, S.R. 264
CORRIDOR STUDY
TABLE OF CONTENTS
Executive Summary
Page
Number
6
Foreword. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
Corridor Transportation Characteristics 24
Potential Corridor Needs 43
Corridor SUfficiency Ratings 47
Traffic Analysis of Corridor Routes 58
Ultimate Development Concept..•....•............. : ...•...... 79
Prepared by Arizona Department of Transportation,
Transportation Planning Division
Production Dates
8-9-91
1
EXHIBIT
NUMBER
1
2
3
4
5
6
7
8
9
10
11
12
13
LIST OF EXHIBITS
Page
Number
Five Year Construction 8
Short and Long Range Improvements 12
study Area Map.................................. .. 18
U.S. 191, Corridor Segment Map 21
S.R. 87, Corridor Segment Map 22
S.R. 264, Corridor Segment Map 23
l\T",......"'""~,.... ,...OF Lanes and Rights-of-Way, u.s. 191 ..•.... 25 .&.'\,,4J,LUJ~.L "" ...
Number of Lanes and Rights-of-Way, S.R. 87 ........ 25
Number of Lanes and Rights-of-Way, S.R. 264 ....... 25
All Routine Maintenance Activities-Cost Per Mile .. 27
Reported Accidents 1986-89 U.S.191, S.R.87,
S.R. 264 29
Injuries and Fatalities 1986-89 U.S.191,
S.R.87, S.R.264 .. 30
Accident by Type 1986-89 31
14 Drivers' Physical Condition 1986-89 33
15 Hierarchical Accident Comparisons on Segment 2 .... 33
16 Attributing Factors to Accidents on U.S. 191 34
17 Hierarchical Accident Comparisons on Segment 5 .... 39
18 Attributing Factors to Accidents on S.R. 264 40
19 Analytic Model Roadway Cross-section Potential
Improvements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 44
20
21
Analytic Model Structure Potential Improvements ... 45
Level of Development Concept, 1991-2000 Potential
Corridor Investment Requirements 46
2
22 1988 Pavement Life SUfficiency Map 51
23 Pavement Life Sufficiency Ratings 51
24 1988 Accident Rate SUfficiency Map 52
25 Accident Rate SUfficiency Ratings 52
26 1988 Accident Severity SUfficiency Map 53
27 Severity Rate Sufficiency Ratings 53
28 1988 Current Daily Traffic Per Lane
SUfficiency Map.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54
29 Current ADT SUfficiency Ratings 54
30 1988 Future Daily Traffic Per Lane
Sufficiency Map.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 55
31 Future ADT SUfficiency Ratings 55
32 1988 Deficiencies Map 56
33 Deficiency Factor Ratings 56
34 Composite SUfficiency Map 57
35 Composite SUfficiency Ratings 57
36 Actual and Projected ADT U.S. 191,
S.R. 87, S.R. 264 -i.e ••••••••• 58
37 Actual and Projected ADT U.S. 191, 1980-2010
by segment........................................ 59
38 Actual and Projected ADT S.R. 87, 1975-2010
by segment ,.,..;I;I;I;I.. 60
39 Actual and Projected ADT S.R. 264, 1975-2010
by segment........................................ 60
40 Population of Apache, Coconino and Navajo
Counties 1980-2010 64
41 Population of Navajo Nation 1980-2010 65
42 Population of Hopi Reservation 1980-2010 66
43 Population of Fort Defiance 1980-2010 67
44 Population of Window Rock 1980-2010 68
3
Population of
Population of
Population of
Population of
Population of
50 Forecast Rates of Change in Personal Income,
Arizona vs. united states 75
51 Forecast Rates of Change in Population,
Arizona vs. united States 76
52 Projected Average Annual Rates of Population
Growth 1989-1999, united states, Arizona,
Corridor Counties 76
53 Projected Average Annual Rates of ADT Growth
1989-1999 U.S. 191, S.R. 87, S.R. 264 77
54 Potential Short Range Highway Improvements 79
55 Potential Long Range Highway Improvements 82
56 Ultimate Development Concept, Short and Long
Range Potential Corridor Investment Requirements .. 85
4
Appendices
LIST OF APPENDICES
Page
Number
Appendix
Appendix
Appendix
Appendix
Appendix
A - Local Government Guidelines For Driveways ..... 87
B - Driveways and Access Management References .... 88
C - Accident Data U. S. 191 ........................ 89
D - Accident Data S .R. B7 ••••••••••••••••••••••••• 91
E - Accident Data S.R. 264 ........................ 92
Appendix F - Level of Development 94
Appendix G - Remedy Actions ...•............................ 96
Appendix H - Level of Development Concept, Analytic Model .. 98
Appendix I - Average Annual Pavement Preservation
Expenditures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 99
Appendix J - Routine Maintenance Cost Per Mile 100
Appendix K - Factors For Future Price Levels 101
Appendix L - H.U.R.F. Forecast Breakdown Into Commercial
And Non-Commercial 102
Appendix M - Estimated Corridor Revenue, Constant
1990 Dollars 103
Appendix N - Estimated Corridor Revenue, Current Dollars ... 104
Appendix 0 - Roadway Improvement Comparison 105
Appendix P - Five Year Construction Program 106
5
EXECUTIVE SUMMARY
Highways as a mode of transportation hold a significant market
share of goods and people both within and throughout Arizona. A
cost efficient and land use effective highway system is an
essential ingredient for the economy of Arizona. without an
adequate highway system, it is difficult to attract and maintain
economic activity.
ADOT has recognized the need to develop a comprehensive and
cooperative effort to insure that travel corridors are analyzed to
identify important components of the transportation network. In
fulfilling this important responsibility, ADOT has undertaken an
analysis of u.s. 191, S.R. 87, and S.R. 264 as travel corridors.
The statutory power to prioritize projects is placed with the
State Transportation Board, a seven me~her panel appointed by the
Governor. The Transportation Board is assisted in setting
priorities by a committee appointed by the ADOT Director known as
the Priority Planning Committee. Annually, ADOT publishes the
prioritized projects in a document title "Arizona's Five-Year
Transportation Facilities Construction Program". For your
convenience, improvement projects on u.s. 191, S.R. 87, S.R. 264
as reported in the construction program are presented on the
following page.
6
HIGHWAY IMPROVEMENTS AS IDENTIFIED
IN FIVE-YEAR CONSTRUCTION PROGRAM
(AS OF 5/91)
U.S. 191
Begin Milepost
11
23*
74
74
s. R. 87
Begin Milepost
361. 7
S.R. 264
Begin Milepost
359.6
367.0
373.9
402.9
446.0
446.0
470.0
474.0
475.0
N.A.
Approximate Length
in Miles
11. 9
14.6
0.4
13.8
Approximate Length
in Miles
6.3
Approximate Length
in Miles
13.3
0.3
10.1
23.1
0.6
2.0
2.6
2.0
0.1
N.A.
Type of Work
Double Chip Seal Coat
AC, Seal Coat & Guardrail
Lighting, SWlk, Turn Signals
SAMI, Overlay
Type of Work
AC, Seal Coat & Spot Level
Type of Work
Asphaltic Concrete (AC)
Intersect~on Improvement
AC, Seal Coat
AC, Seal Coat
Intersection Improvement
Landscape & Irrigation
Design Concept Study
Landscape & Irrigation
Signal Improvement, C&G & AC
Fence & Cattle Guard (Material
Only-Joint Project)
* Project underway
See Exhibit 1 for graphic illustration of improvements.
7
EXHIBIT 1
FIVE-YEAR CONSTR,UCTION PROGRAM
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Construction Projects
8
INTRODUCTION
Potential short and long range highway improvements have been
identified using the ultimate development and level of development
concepts. Identified improvements and their associated costs for
both concepts are listed for U.S. 191 and state Routes 87 and 264.
Also listed for each route are pavement preservation and routine
maintenance costs to complete the picture of anticipated expenses.
Forecast traffic is summarized to facilitate comparisons between
routes. The executive summary ends with a brief listing of land
use and safety findings. Additional data and findings are
presented throughout the document "u. S . 191 , S . R. 87, S . R. 264
Corridor study".
ULTIMATE DEVELOPMENT AND LEVEL OF DEVELOPMENT CONCEPTS
The ultimate development concept in rural areas is normally a
single roadway prism with two through-traffic lanes, full
shoulders and· passing lanes in selected locations. In urban
areas, the through-traffic lanes may be expanded to four lanes
with curb and gutter. This concept allows numerous lengthy
reconstruction projects which are designed to ultimately fit
maximum standards. This is in contrast to the level of
development concept which allows limited reconstruction projects
of limited length with less than maximum planning standards.
The following illustrated improvements are based on analysis of
service, quality and facility condition of corridors in concert
with the ultimate development concept.
See Exhibit 2 for graphic illustration of potential short and long
range improvements using the ultimate development ,concept.
9
CORRIDOR U.S. 191
POTENTIAL HIGHWAY IMPROVEMENTS
ULTIMATE DEVELOPMEN~ CONCEPT
SHORT RANGE
o Overlay or reconstruction of approximately eighty-three (83)
miles of roadway
o Make structure improvements to Cottonwood and Chinle bridges.
o Make improvements to junctions U.S. 191 (South) and S.R. 264;
U.S. 191 (North), S.R. 264 and Indian Route 15.
o Overlay or reconstruction of approximately
roadway.
(Q\
\ .... , miles of
o Widen approximately five (5) miles of roadway.
o Make structure improvements to Agua Sal bridge.
o Improve or modify fencing along twenty (20) miles of roadway.
o Flatten roadway slopes for approximately twenty (20) miles of
roadway.
o Implement an access control and driveway man~gement plan.
CORRIDOR S.R. 87
POTENTIAL HIGHWAY IMPROVEMENTS
ULTIMATE DEVELOPMENT CONCEPT
SHORT RANGEl
o Overlay or reconstruction of approximately twenty-seven (27)
miles of roadway.
lLong range improvements were not identified.
10
CORRIDOR S.R. 264
POTENTIAL HIGHWAY IMPROVEMENTS
ULTIMATE DEVELOPMENT CONCEPT
SHORT RANGE
o Overlay or reconstruction of approximately thirty-three (33)
miles of roadway.
o Make structure improvements to Moenkopi, Dinnebito, Jeddito,
Ganado and Fish bridges.
o Make improvements to junctions S.R. 264 and Indian Route 6;
S.R. 264 and Indian Route 12 (North).
o Construct cliInbing lanes at two locations with one mile
minimum length.
LONG RANGE
o Overlay or reconstruction of approximately fifty-one (51)
miles of roadway.
o Make structure improvements at five locations.
o spot widen at two locations for approximately one mile in
length.
o Add lanes at two locations for a total of app'roximately four
(4) miles.
o Construct climbing lanes at three locations for a total of
approximately six miles.
o Improve or modify fencing along fourteen (14) miles of
roadway.
o Flatten roadway slopes for approximately five (5) miles of
roadway.
o Implement an access control and driveway management plan.
11
EXlIIBIT 2
i P~TE~NTIAL ~SHORT ~ AND LONG
RANG~ tMPROVEMENTS
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.SHORT RANGE IMPROVEMENTS
lONG RANGE' IMPROVEMENTS
12
The following identified improvements are based on analysis of
service quality and facility condition of corridors in concert
with the level of development concept.
POTENTIAL HIGHWAY IMPROVEMENTS
LEVEL OF DEVELOPMENT CONCEPT
CORRIDOR U.S. 191
SHORT RANGE
o Reconstruction of approximately one-quarter mile of roadway.
o Overlay approximately eighty-six (86) miles of roadway.
o Make structure improvements to Cottonwood and Chinle bridges.
LONG RANGE
o Overlay approximately fourteen (14) miles of roadway.
o Make structure improvements to Agua Sal bridge.
CORRIDOR S.R. 87
SHORT RANGE
o Overlay approximately forty-five (45) miles of roadway.
CORRIDOR S.R. 264
SHORT RANGE
o Make structure improvements to Moenkopi, Dinnebito, Jeddito,
Ganado and Fish bridges.
LONG RANGE
o Overlay approximately one mile of roadway.
o Make structure improvements at five locations.
13
POTENTIAL TRAFFIC AND INVESTMENT REQUIREMENTS
Financial resources provide a vital element for meeting transportation
requirements. To address these requirements, ADOT has relied on
transportation user fees. Obtaining sufficient financial resources to
implement potential improvements is a continuous statewide challenge.
Estimated costs under both the ultimate and level of development concepts
are minimum amounts required. Actual costs are likely to be higher. This
system-wide financial challenge requires judicious evaluation of actual
construction projects. Criteria traditionally applied includes the belief
that transportation users bear an appropriate share of the costs of
facilities they use and that those who are paying user charges will benefit
from them.
The following chart, which summarizes future traffic and investment
requirements, provides useful information for financial analysis purposes.
FUTURE TRAFFIC AND POTENTIAL
CORRIDOR INVESTMENT REQUIREMENTS
($1,000 1988 Prices)*
COFRIDOR
FUTURE TRAFFIC A
Average Daily
Traffic
u.s. 191
1,800
s. R. 87
1,200
S.R. 264
7,500
TOTALS
N/A
702
Million Vehicle
Miles Traveled (V.M.T) 204 2,094 N/A
VARIABLE COSTS
Ultimate Development
Concept (D.D.C.)
Level of Development
Concept (L.D.C.)
FIXED COSTS
Pavement
Preservation
Routine
Maintenance
COST TOTALS
U.D.C./
Cost Per V.M.T.
L.D.C./
Cost Per V.M.T.
$17,245
$14,526
$ 6,294
$ 5,822
$29,361/
4.1¢
$26,642/
3.8¢
$3,942
$3,408
$2,925
$1,504
$8,371/
4.1¢
$7,837
3.8¢
$22,294
$ 1,631
$ 7,456
$ 9,371
$39,121/
1. 8¢
$18,458
0.9¢
$43,481
$19,565
$16,675
$16,697
$76,853
$52,937
*Rounded
A=1991-2000 Time Period
14
LAND/USE MANAGEMENT OF HIGHWAY ACCESS
1. Enhance coordination efforts between ADOT, federal agencies,
tribal and local governments in providing adequate setbacks and
ingress/egress control. Diligent attention will be required from
the Bureau of Indian Affairs, Housing and Urban Development, and
ADOT to ensure that proper development and highway compatibilities
are provided for in future development.
2. Future residential commercial and recreational developments
should be encouraged to develop in planned cluster districts or
other such designs which enhance the function of state highways
and avoid the proliferation of access points to the highway.
3. ADOT in conjunction with the Bureau of Indian Affairs,
Housing and Urban Development, and tribal Governments should
develop enhanced administrative procedures to obtain needed
rights-of-way, borrow and storage sites for proposed highway
improvements. Obtain from B. I .A. financial assistance to the
state when local growth, development opportunities demand roadway
improvements. Require developers and land owners to dedicate
needed rights-of-way and provide financial assistance to the state
in conjunction with governing authorities when development
opportunities demand roadway improvements.
4. Due to the unique sovereign status of Indian land, ADOT,
tribal governments and B.I.A. should develop policies, procedures,
regulations and statues that reduce conflicts which hamper normal
operational aspects of state routes. Enhancement of the
operational environment could result in reduced transportation
costs and better service.
5. ADOT's Transportation Planning Division should take the lead
role with research and development of rules concerning access
management on State roadways as a possible lower cost alternative
to the traditional methods of improving travel time and safety.
TRANSPORTATION SAFETY
1. A.DOT in conjunction with tribal governments, the Bureau of
Indian Affairs, and the Department of Health and Human Services
should implement methods to improve training for accident
investigators and to improve administrative procedures for the
filing of accident reports with DOT. The lack of precision in
data collection and reporting may create difficulty in detecting
potential hazards and advances cost inefficient transportation.
2. Alcohol is a significant contributing factor to accidents on
state highways. ADOT, in conjunction with tribal governments, the
Bureau of Indian Affairs and the Department of Health and Human
Services, should consider implementation of community awareness
15
programs intended to inform the pUblic about the dangers of
drinking and driving to reduce the alcohol-related accidents.
Another option is stepped-up patrol of highways.
3. Numerous accidents also result from vehicles striking animals
on the highway. ADOT in conjunction with tribal governments, the
Bureau of Indian Affairs, and the Department of Health and Human
Services should consider implementation of community awareness
programs intended to reduce the high rate of animal incidents.
Enhanced enforcement of animal control should also be
investigated.
4. In some urbanizing areas, properties abutting the highway have
numerous driveways and streets which are frequently offset. Highly
unregulated access coupled with offset streets promotes traffic
conflict on the highway. ADOT in conjunction with tribal
governments, and the Bureau of Indian Affairs should investigate
methods and locations which reduce traffic conflict caused by
unregulated access and offset street intersections. -
16
FOREWORD
The transportation systems in Arizona have had a significant
impact on the growth of the economy, the utilization of land, and
the life styles enjoyed by citizens throughout the state.
Transportation facilities serve all regions of the state; they are
connecting links as well as arterials over which flow the goods
and services essential to every day living. u.s. 191, S.R. 87,
and S.R. 264 are three of these connecting links located in
Northeastern Arizona. (See Exhibit 3).
ADOT has recognized the need to develop a comprehensive and
cooperative effort to insure that these travel corridors are
analyzed and remain important components of the transportation
network. In fulfilling this important responsibility, ADOT has
undertaken an analysis of these three corridors. The analysis
reviews existing characteristics and identifies the short term and
the long range potential needs (6 + years) for transportation
improvements within the three travel corridors. Where applicable,
recommendations for short and long term improvements to meet these
needs are listed.
It should be emphasized that the purpose of this study is not to
identify detailed engineering solutions, but to highlight existing
and future capacity and/or operational problems. An environmental
inventory/assessment is beyond the scope of this report. This
data collection process did not involve review of documents, plans
and studies relevant to: threatened and endangered species;
archaeological, historical, or architecturally significant
properties; parks or recreational facilities, prime agricultural
lands; noise sensitive receptors; air quality; geologic hazards;
mineral resources or floodplains. However this study does tend to
focus on desires and what is affordable.
Further study efforts are necessary to develop engineering reports
and implementation plans. Proposed highway improvements identi­fied
through technical studies such as a Corridor Study typically
far exceed the available revenue over a five year construction
program. The inclusion of a problem or identification of a
proposed improvement in this document does not indicate that it is
of sufficient priority on a statewide basis to receive a portion
of the limited funding available. However, it does lead to the
next and most difficult phase of the programming process:
prioritizing highway improvements. The statutory power to
prioritize projects is placed with the State Transportation Board,
a seven member panel appointed by the Governor.
17
EXHIBIT 3
STUDY AREA
Study
Area.
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MILES
18
50
INTRODUCTION
UNITED STATES ROUTE 191
This corridor, located entirely in Apache County, begins at the
junction with Interstate 40 near Chambers, and extends northerly
to the junction of State Route 264 at the Navajo settlement of
Ganado. At this location, united States Route 191 overlaps state
Route 264 and continues west for approximately six miles until the
junction of Indian Route 15, state Route 264 and United states
Route 191 (U.S. 191). At this junction, U.s. 191 extends norther­ly
through the Navajo settlement of Chinle, Many Farms and Round
Rock to the junction with U.s. Route 160 near the settlement of
Mexican Water. The corridor does not include the portion of U.s.
191 from u.s. 160 to the Utah State Line. This portion is
administered by the Bureau of Indian Affairs.
To facilitate analysis of data, this corridor has been divided
into two segments. The first segment is between Chambers and
Ganado for a distance of 37.63 miles. The topography in this area
consists of rolling and flat plateau desert with elevations in the
6,000 foot range. Segment two is 92.49 miles in length between
Ganado and Mexican Water. This segment's topography also consists
of flat and rolling desert with elevations of 6,000 feet at the
southern end to 5,000 feet on the northern portion. The total
corridor length is 130.12 miles. A segment map of the U.s. 191
corridor is shown in Exhibit 4.
STATE ROUTE 87
This corridor, located entirely in Navajo County, begins at the
junction with Interstate 40 near Winslow, and extends northerly to
the junction of State Route 264 at the Hopi settlement of Second
Mesa. Approximately 16 miles of this corridor is located off the
reservation and about 44 miles are on the Navajo Nation and Hopi
ReserVation. Corridor topography consists of flat desert with
elevations ranging from about 4,800 feet near Winslow to over
6,000 feet at the junction of State Route 264. A segment map of
the S.R. 87 corridor is shown in Exhibit 5. The total corridor
length is 60.47 miles.
19
STATE ROUTE 264
This corridor begins at the junction of united States Route 160
near Tuba city and extends easterly through Coconino, Navajo and
Apache Counties to the Arizona - New Mexico State Line. This
route begins and ends in the Navajo Nation yet passes through the
Hopi Reservation.
This corridor has been divided into five segments to facilitate
analysis of data. The first segment is between the Navajo settle­ment
of Tuba City (milepost 321.97) and the Hopi settlement of
Second Mesa (milepost 384.21) for a total distance of 62.24 miles.
The topography for segment one consists of rolling and flat
plateau desert with elevations around 4,600 feet. Segment two
starts at milepost 384.21 which is also the junction with S. R. 87
and ends at the junction of U.S. 191 or milepost 446.89 near
Ganado, a distance of 62.68 miles. The topography of segment two
is typically flat to rolling desert with elevations ranging from
4,000 to over 6,000 feet. Segment three consist of a two-mile
length of highway through the Navajo settlement of Ganado. Segment
four starts at milepost 448.89 and ends at milepost 471.62 near
St. Michaels, a distance of 22.73 miles. Near Ganado, the roadway
elevation climbs from 6,300 feet to over 7,700 feet at the Summit
and than descends to about 6,800 feet in the st. Michaels area.
Segment five, the last segment, is a 4.50 mile length of highway
connecting st. Michaels, Window Rock and the state line at
milepost 476.12. Segments for S.R. 264 are shown in Exhibit 6.
20
US 191 SEGMENTS
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EXHIBIT 4
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MILES
SEGMENT NO. MILEPOST LOCATION LENGTH
CD 0.00 37.63 37.63
® 43.85 136.34 92.49
TOTAL MILES 130.12
21
EXHIBIT 5
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SR 87 SEGMENTS
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MILES
SEGMENT NO. MILEPOST LOCATION LENGTH
CD 345.57 - 406.04 60.47
22
EXHIBIT 6
SR 264 SEGMENTS
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MILES
SEGMENT NO. MILEPOST LOCATION LENGTH
CD 321.97 384.21 62.24
® 384.21 446.89 62.68
® 446.89 448.89 2.00
@) 448.89 471.62 22.73
® 471.62 476.12 4.50
TOTAL MILES 154.15
23
CORRIDOR TRANSPORTATION CHARACTERISTICS
In the following pages, historical characteristics are identified
in terms of existing rights-of-way, surface maintenance costs, and
accident statistics. Corridor analyses include these characteris­tics
as they can help highlight problem areas that may need
corrective action. Pavement deterioration, including cracks and
crumbling edges, are indications of sub-grade or surface failure
which will lead to high maintenance costs.
Some of the sources consulted for this corridor study include the
current Five Year Highway Construction Program, (1990-94)
accident records, the State Highway System Log, the State Traffic
Log, sufficiency ratings, bridge records and population data.
RIGHT-OF-WAY
In most cases, right~of-way in these corridors appears to be
adequate to provide for future projects. There is at least 200
feet of right-of-way on each route with the exception as noted
below and in the exhibits. u.S. 191 segment 2 has some mileage
with right-of-way limited to 80 feet. On S.R. 264, segment 1 has
limitations of 100 feet through Moencopi; segment 4 has some
mileage with 150 feet and segment 5 has a significant amount of
right-of-way limited to 100 feet.
If any of these segments were to be reconstructed or widened, then
additional right-of-way might be necessary. Exhibit 7 shows the
number of lines and rights-of-way for u.S. 191, Exhibit 8 shows
S.R. 87, and S.R. 264 is shown in Exhibit 9.
Specific right-of-way requirements for major improvement projects
are precisely known once the engineering plans have been devel­oped.
For proposed projects to rapidly proceed to construction,
it is vital to mitigate right-of-way and access disputes. Time
delays and their associated expense are frequently encountered
when DOT finds it necessary to acquire right-of-way as part of an
improvement project. This is especially critical when projects
are located within the Navaj o-Hopi j oint use disputed areas.
These difficulties increase the risk of allocated financial
resources being reallocated to projects that can be implemented in
an expeditious manner.
Due to layering and overlapping roles of governments (i.e. Bureau
of Indian Affairs, Tribal Council and Chapter House, State and
County Government) it can be difficult to determine "rights" and
"authority" concerning matters of highway right-of-way and access.
A reduction in the layering of government would relieve the time
spent processing projects on the Indian reservations. It is not
anticipated that this issue will be resolved in a timely manner.
24
LOCATION
EXHIBIT 7
NUMBER OF LANES AND RIGHTS-OF-WAY
U. S. 191
NUMBER OF LANES
R.O.W.
AVAILABLE
SEGMENT 1
MP 0.00-37.63
SEGMENT 2
MP 43.85-136.34
(MP 73.22-74.31)
2 Travel Lanes
2 Travel Lanes
(4 Travel Lanes)
200 feet
80-250 feet
LOCATION
SEGMENT 1
MP 345.57-406.04
EXHIBIT 8
NUMBER OF LANES AND RIGHTS-OF-WAY
S = R= 87
NUMBER OF LANES
2 Travel Lanes
D n TAl
.I"\.. V • r., •
AVAILABLE
200 feet
LOCATION
SEGMENT 1
MP 321.97-384.21
EXHIBIT 9
NUMBER OF LANES AND RIGHTS-OF-WAY
S. R. 264
NUMBER OF LANES
2 Travel Lanes
R.O.W.
AVAILABLE
100-200 feet
SEGMENT 2
MP 384.21-446.89
(MP 403.02-403.41)
SEGMENT 3
MP 446.89-448.89
SEGMENT 4
MP 448.89-471.62
SEGMENT 5
MP 471.62-472.63
(MP 472.63-476.12)
2 Travel Lanes
(4 Travel Lanes)
2 Travel Lanes
2 Travel Lanes
2 Travel Lanes
(4 Travel Lanes)
25
150-200 feet
200 feet
150-200 feet
100-200 feet
PAVEMENT SURFACE MAINTENANCE
ADOT's goal in maintenance activities is the preservation and
restoration of the State's roadways and related facilities. These
activities are broken down into specific work responsibilities and
into segments, based on variations in traffic volume, user
characteristics, and adjacent land uses.
Previous corridor studies used routine pavement surface
maintenance costs as a major method to locate pavement
deficiencies. The surface maintenance costs over a three year
period were used to identify deficiencies. These deficiencies were
generally a symptom of problems associated with unstable soils or
drainage of base materials which, given time, resulted in
deficient surface pavement. This condition would prompt
maintenance expenditures on surface pavement.
This analytical method was devised to estimate costs of routine
maintenance which consists of patching, sealing and seal coating
the roadway surface. Application of this statistic indicates
specific sections of roadway that require frequent or extensive
surface maintenance or extensive reconstruction of roadway base.
This study's analysis and application of routine maintenance costs
has departed from the previous method used to calculate routine
maintenance costs. In addition to surface maintenance costs, the
sUfficiency rating system is also used as an indicator of roadway
sections in need of reconstruction or overlay.
This report considers all maintenance costs including traffic
control, overhead activities, and snow and ice removal. This
change now reflects the costs of maintaining stat~ highways.
In order to provide a relative measure of maintenance costs, the
following table was developed for use in other corridor studies.
ALL ROUTINE MAINTENANCE
Low
Medium
High
ACTIVITIES-COST PER
$ 0 to
$2,800 to
$5,700 or
MILE OF
$2,799
$5,699
Greater
ROADWAY
Corridor maintenance cost have been calculated for 1986 (07/86­12/
86), 1987, 1988, and 1989 (01/89-07/89). Costs for all
corridor segments are shown in Exhibit 10. Of the approximately
345 miles of highway under study, about 80 percent of this mileage
is in the low to medium maintenance cost range. However, of the
five corridor segments for S.R. 264, the remaining 20 percent of
high cost mileage is found in three corridor segments. Two of
these high maintenance cost segments encompass areas primarily
near small urban areas--those near Second Mesa and Window Rock.
Those segments have an average maintenance cost of $6,421 and
$8,074 per mile, respectively.
26
EXHIBIT 10
ALL ROUTINE MAINTENANCE ACTIVITIES-COST PER MILE
u. S. 191
SEGMENT
1989 (1/2 yr. ) AVERAGE
SEGMENT
NUMBER
1
2
1
1
2
3
4
5
1986 (1/2 yr.)
$2058
3800
$973
$1685
3119
2214
1304
1951
$4179
3957
S. R. 87
$1884
S. R. 264
$5783
5676
5902
4109
9749
27
$6080
2540
$4107
$4933
4044
6189
5537
6522
$1542
2685
$497
$4285
4894
4958
2325
6001
$4620
4327
$2487
$5562
5911
6421
4425
8074
CORRIDOR ROADWAY ACCIDENT DATA
ADOT's Traffic Records Unit compiles data on a statewide basis
from accident reports which are submitted by state and local
governments as well as reservation agencies. This database was
accessed and historical accident data over a four-year period from
1986 to 1989 is presented in this section as a general review of
accidents. ADOT's Traffic Records unit produces standardized
reports which contain data on the type of accident, time, date and
location of accident.
The traditional debate on the causes of traffic accidents has been
whether the highway, the vehicle, or the driver "caused" a given
accident. In the overwhelming majority of traffic accidents, the
single cause (factor) approach represents a gross over-simplifica­tion.
A more complex system of multiple variable exists in the
environment of traffic accidents. Identification of those
combinations of factors responsible for accidents requires
comparing accidents for consistent factor combinations with and
without the safety related features being studied. This identifi­cation
of factor combinations is beyond the purpose of this
corridor report.
An objective of this report is to identify potential problems and
place them into perspective so that effective countermeasures can
be developed and evaluated for subsequent implementation. Conclu­sions
derived from accident, travel and geometric data are
essential to identify study areas, identify promising countermea­sures,
and to evaluate the effectiveness of countermeasures.
However, accident data alone cannot provide a definitive answer.
Prevention of accidents relies on a systematic ~ approach which
addresses several factors. continued improvements to safety
depend upon acceptance and application of proven techniques which
address the broad spectrum - the highway, the vehicle, and the
driver. Roadway accident data presented in this section is an
alternative and complimentary method to the Sufficiency Rating
System for reviewing corridor safety. The review of accident data
presented in the report is just a small part of a systematic
approach.
u.s. 191
Over the four-year study period, a total of 361 accidents were
reported on U.S. 191. Exhibit 11 shows the frequency distribution
of these accidents by segment. The majority of accidents occurred
on segment 2. These accidents yielded 202 injuries and 14
fatalities as shown in Exhibit 12.
28
EXHIBIT 11
REPORTED ACCIDENTS 1986-1989*
Route
u.s. 191
Segment 1
Segment 2
Total
s. R. 87
Segment 1
S.R. 264
Segment 1
Segment 2
Segment 3
Segment 4
Segment 5
Total
Milage
37.63
92.49
130.12
60.47
62.24
62.68
2.00
22.73
4.50
154.15
Total Accidents
74
287
361
51
90
140
15
130
130
505
Percentage
20.5
79.5
100.0
100.0
17.8
27.8
3.0
25.7
25.7
100.0
* Note: Unless otherwise noted the accident data presented in
this study includes all types of reported accidents, and
data on accident locations was reviewed and is presented
in an aggregate manner unless otherwise noted. The
comparisons between accident type percentages on given
highway sections to statewide accident type percentages
may not be valid statistical comparisons.
29
EXHIBIT 12
INJURIES AND FATALITIES 1986-1989
vovn - 23~1% 5 - 16.1% 85
91 - _, _D_ o ''It:: 09.- 00 ~o.,<:'6 0 G..J. u-o -' -'
13 - 3.7% 0 - 0.0% 13
110 - 31. 7% 9 - 29.0% 119
46 - 13.3% 9 - 29.0% 55
347 - 100.0% 31 - 100.0%
Route
U.S. 191
Segment 1
Segment 2
Total
S. R. 87
Segment 1
S.R. 264
Segment ...,.
Segment 2
Segment 3
Segment 4
Segment 5
Total
Injuries/Percentage
54 - 26.7%
148 - 73.3%
202 - 100.0%
56 - 100.0%
Fatalities/Percentage
5 - 35.7%
9 - 64.3%
14 - 100.0%
4 - 100.0%
Total/
Number
59
157
60
Knowledge of accident types and operator's physical condition may
provide trends which can be contrasted to other routes. Exhibit
13 illustrates the primary types of accidents o~curring on this
highway annually. For the entire corridor, the single largest
category of accident type involves animals; this accounted for 25
percent of all accidents reported.
statewide incidents of animal/vehicle traffic accidents on rural
roads, streets as well as state highways for 1989 accounted for
5.8% of the total accidents. If this data source is a reference
mark, then a high rate of animal incident occurs on U. S. 191.
Another interesting observation is found in Exhibit 13 pertaining
to the category "rear-end" collision which accounted for 11
percent of all reported accidents on this rural roadway.
contrasting this percentage to 1989 rural statewide figures, the
category "following to closely" accounted for 1.6 percent of total
contributing circumstances. The 11 percent figure appears unusual
for 130 miles of rural roadway. However, it is important to
remember the contrasting reference mark uses 1989 statewide data
which includes mUltiple combination of factors (i.e., reported
accidents at 96,225 with 195,083 contributing circumstances), as
well as data from counties, cities and towns.
30
EXHIBIT 13
ACCIDENT BY TYPE 1986-1989
u.s. 191 S.R. 87 U.S. 264
Number/Percentage Number/Percentage Number/Percentage
Ran-Off
Roadway 72 - 20.0% 15 - 29.4% 116 - 23.0%
Hit Animals 90 - 25.0% 2 - 3.9% 86 - 17.0%
Rear End 39 11.0% 2 - 3.9% 67 - 13.3%
Over-Turned
In Road 32 - 9.0% 12 - 23.5% 40 - 7.9%
Turning Left 23 - 6.0% 2 - 3.9% 18 - 3.5%
Hit Fixed
object ., k 11 ,g.. 6 - 11. 8% 27 - 5.3% .J....J ""%;l~O
Other 90 24.9% ~ .., ..,., cg. , ~, 30.0% .!.~ ~-J.U-O ..........
Total 361 - 100.0% 51 - 100.0% 505 - 100.0%
The most significant type of accidents occurring on segment 1
include: automobiles running off of the roadway - 26 out of 72
accidents yielding 35 percent for segment 1 and, autos striking
animals on the roadway - 16 out of 90 accidents netting 22 percent
for segment 1. The number of accidents involving hit animals were
greatest on segment 2 and exceeded by 4 times the 1989 rural
statewide percentage of 5.8. Other frequent accident types were
run-off roadway and rear-end collisions at 16 _and 13 percent
respectively. Rear-end accidents were predominately found in
segment 2 and particularly in the Chinle vicinity.
The accident category "ran-off road" can be associated with the
physical condition of the driver. Alcohol and fatigue could have
been contributing factors for some of these accidents.
One out of five accidents were caused by striking animals. It
appears the inability to contain the grazing animals often located
adjacent to the highway plays a significant role in this type of
accident. While fences, gates and cattleguards have been con­structed
in these areas to contain animals, these fences are
frequently vandalized and gates are left open to facilitate in the
feeding or transfer of animals.
ADOT has historically provided fencing materials for the construc­tion
of fences along highways. Labor for the construction of
these fences has been supplied locally by the respective Indian
Tribe. Two methods are identified to mitigate this type of
accident in areas frequented by grazing animals both in and near
31
villages. The methods range from changing the typical fencing
material--barbed wired--to a woven wire that is less inclined to
be pushed down by animals and cut by humans. In areas where
animals must be moved across the highway to graze, gates might be
considered instead of cattleguards. Designs of cattleguards which
allow for self-cleaning used in combination with paving the turn­outs,
should also be considered. These mitigation measures are
worthy of consideration especially for highways in or near
villages to bridle animals from the right-of-way. It is
anticipated that all the methods identified will be more
expensive. It is unknown if the additional expense will curb
animal access.
Data regarding physical condition of the driver indicate numbers
which are perhaps unusual. Exhibit 14 also shows that in 51
accidents or 10.4 percent it was not known if alcohol was a
contributing factor. However, for nearly 15 percent of the
accidents, alcohol was a contributing factor and fatigue accounted
for 4 percent. Contrasted to the 1989 statewide reference mark of
driver physical condition, 5 percent had been drinking; and just 2
percent of the accidents were in part caused by sleepy, fatigued
drivers and other defects.
Segment 1 data indicates that 34 percent of the accidents were
attributed to alcohol. Alcohol was a contributing factor in 11
percent of the accidents for segment 2. Although this percentage
is less than segment 1, segment 2 is still more than double the
1989 statewide percentage of 5 percent.
Review of the 1988 Accident Rate SUfficiency system indicated a
total of five miles between mileposts 70.00 and 80.00, and nine
miles overall are considered "poor" on segment 2. This incited a
review of accident records which found that a disproportional
share of accidents occurring on segment 2 fell within a 10-mile
section of roadway between mileposts 70.00 and 80!00. The number
of accidents on this 10-mile section of roadway was discovered to
be half of the total number of accidents occurring on segment 2 of
U.S. 191. Over the 4-year study period, 144 accidents resulting
in 61 injuries and 2 fat~lities occurred on this section. The
findings prompted an even greater analysis of this section of
roadway. A further delineation of accidents indicated that 25
percent of the accidents over the 4-year period occurred on a
1.09-mile section of U.S. 191 in or near the vicinity of Chinle.
These findings are summarized in Exhibit 15.
32
EXHIBIT 14
DRIVERS' PHYSICAL CONDITION 1986-1989
u.s. 191 S.R. 87 S.R. 264
Number/Percentage Number/Percentage Number/Percentage
No Apparent
Defects 348 - 70.7% 24 - 38.1% 504 - 69.6%
Unknown 51 - 10.4% 18 - 28.6% 78 - 10.8%
Alcohol
Related 73 - 14.8% 13 - 20.6% 108 - 14.9%
Sleepy/Fatigue
and Other 20 - 4.0% 8 - 12.7% 34 - 4.7%
Total* 492*- 100.0% 63*- 100.0% 724*- 100.0%
*NOTE: Figures reported in the total column of Exhibit differ
from figures reported for total accidents. This is due
to reporting of physical condition of each driver in
two-vehicle accidents.
EXHIBIT 15
Hierarchical Accident Comparisons on Segment 2
% of
1989 Total Total
Segment 2
M.P. 43.85 ­136.34
Accidents 94
Injuries 43
Fatalities 2
Segment 2
M.P. 70.00 ­80.00
Accidents 52
Injuries 30
Fatalities 1
Segment 2
M.P. 73.22 ­74.31
Accidents 26
Injuries 15
Fatalities 1
91
40
4
48
11
1
20
5
1
33
49
30
2
20
11
o
10
5
o
53
35
1
24
9o
16
7
o
287
148
9
144
61
2
72
32
2
100.0
100.0
100.0
50.0
41.2
22.2
25.0
21. 6
22.2
U. S. 191 is a 4-lane highway for 1. 09 miles between milepost
73.22 and milepost 74.31. The 1.09-mile section of highway was
selected as a study area for this report so that composite
accident data could be compiled from the number of accidents
occurring on the 4-lane section of U.S. 191 in Chinle.
In August 1990, ADOT' s Traffic Studies Branch produced a CLOSE
report; this Candidate Location for an Operations and Safety
Evaluation report investigated a .39 mile section of U.S. 191 in
Chinle. This CLOSE report cited 45 total accidents including 2
pedestrian fatalities occurring over the 1986-88 time period.
The degree of overlap between the number of accidents in the CLOSE
report and the number in Exhibit 16 is difficult to determine.
The CLOSE report identified 45 accidents over a 3-year period in a
rather limited area compared to this report which identified 72
accidents over a 4-year period on an expanded section of U.S. 191.
Each accident from 1986 to 1988 is therefore presumed to be
counted once in each study; this results in a difference of 27
accidents.
L~V...Y...n...1.1.D'.T1n..T£.m ."1I.eV:
Attributing Factors to Accidents on U.S. 191
M.P. 73.22 - 74.31
1986 1987 1988 1989 TOTAL
Total
Accidents* 26 20 10 16 72
Driveway
Access 6 3 3 6 18
Intersection 15 11 4 8 38
Alcohol 1 3 3 0 7
Pedestrian/
Pedalcyclists 3 3 0 0 6
Animals 0 0 2 0 2
Other"'''' 2 2 1 2 7
* NOTE: More than one factor may cause an accident.
** All factors not previously included in above categories.
34
Of the 78 total factor combinations, a total of 18 were attributed
to the large number of indiscriminate turnouts and unaligned
streets abutting u.s. 191. After a review of aerial photographs,
it is apparent that the driveways accessing the highway could
contribute to the number of accidents. The area abutting the
highway has numerous driveways and streets which are offset.
Highly unregulated access coupled with a large number of offset
streets abutting the highway right-of-way promotes traffic
conflict. A prescription for managing access on state highways is
currently being developed, however some steps could be taken in
the interim to help mitigate the situation. Proposed steps might
include the following:
(1) eliminate unnecessary driveways;
(2) provide incentives to construct shared or common
driveways;
(3) develop driveway guidelines--the spacing and
realignment of offset streets and driveways are
no.orlorl ~I""\ rI.o,..".02.c:!O .... }.,.o ~l'ft"""1"\'" 1""\-4= e!;~.o oF"..;,.. ... ; """'"
<!lo.3 ...... .,.,.-...4~"lo4 ,..""'" '!:o4~"'~'!iW>""4Ilii11~ ~~~~ ~4U'-'~.IA~ ~. ~ .. ~.., ~. ";"'\oo;oV"~"'':'1
(4) adopt a circulation plan i plan for future growth
and street system/evaluate site plans for accor­dance
with long range plan; and
(5) provide for highway appurtenances to help direct traffic
(raised medians, curbing and sidewalks).
Additional information regarding the development of access
guidelines can be found in Appendix A and B.
The number of accidents outside the initial CLOSE study area may
suggest that additional inspection of highway might be warranted
in the future. If so, it may justify additional traffic engineer­ing
studies to determine if corrective steps are needed. Poten­tial
concepts to explore are:
• Community Awareness Programs
• Access Control/Driveway Guidelines
• Speed zone reductions
• Sign and pavement markings
• Curb, sidewalks, street lights
Animal control enforcement
• R-O-W fence modification
It is recognized that many accidents are caused by operator error
and in some cases substance abuse. Design-related changes to the
35
roadway will probably not prevent these type of accidents from
reoccurring, however community awareness programs intended to
inform the public about the dangers of drinking and driving may
assist in efforts to prevent alcohol-related accidents.
S. R. 87
During the four-year study period from 1986 to 1989, a total of 51
accidents occurred on the 60.47-mile stretch of S.R. 87~ Accord­ing
to reports issued by Traffic Studies, these accidents caused
56 injuries and 4 fatalities. Please refer to Exhibits 11 and 12.
The most frequent type of accident on this segment of highway were
vehicles running off the road with 15 occurrences or 29 percent.
Exhibit 13 provides a breakdown of the type of accidents. Twenty­four
percent or 12 accidents involved vehicles overturned in the
roadway. Data for drivers' physical condition are found in
Exhibit 14. Alcohol was a factor in 21 percent of the accidents
and fatigue was a factor in 13 percent of the accidents.
S.R. 264
This route is the longest highway under consideration in this
corridor study. Along its 154.15-mile roadway, 505 accidents
were reported during the four-year period. The breakdown of
accidents by segment is shown in Exhibit 11.
Although final figures from Traffic Studies are revised as new
accident records from the reservations are received, recent data
shown in Exhibit 12 indicate that these accidents produced 347
injuries and 31 fatalities over the span of 4 years.
The type of accidents occurring most frequently on S.R. 264
involve vehicles running off the road, 23 percent; hit animals, 17
percent; and rear-end collisions, 13 percent. The type of
accidents occurring most frequently are shown in Exhibit 13.
Fifteen percent of the accidents were influenced by alcohol.
Exhibit 14 also shows that fatigue was a contributing factor in 7
percent of the accidents.
S.R. 264 seqment 1
The 62.24 mile segment comprises 40 percent of the entire route
mileage, only 18 percent of the accidents occurred here. The most
frequent accident type--43 percent of all accidents on this
segment--involved vehicles running off of the roadway. This is
higher than the average of 23 percent for the highway. Vehicle
collision types involving rear-end, striking fixed objects, and
overturning on the roadway contributed another 37 percent to the
overall number of accidents.
36
S.R. 264 Seqment 2
The largest of the segments, this 62.68 mile stretch is 41 percent
of the total route mileage and accounted for 28 percent of all
accidents. Vehicles running off of the roadway or striking
livestock were the cause of 74 accidents--over half of the
accidents on this stretch of highway. This coincides with the
high percentage--71 percent--of accidents (99) that are single
vehicle.
S.R. 264 Seqment 3
This two mile segment is the smallest of the five segments.
Fifteen accidents occurred on this segment of highway resulting in
13 injuries. According to accident reports, no fatalities
occurred on this segment. The small number of accidents prevents
any meaningful hypothesis to be drawn.
S.R. 264 Seqment 4
This 22.73-mile segment of roadway produced nearly one-third of
all injuries occurring on SoRe 264 during the 4-year period; it
also tied segment 5 for the total number of highway fatalities--9.
This segment comprises just 15 percent of the corridor highway
mileage and has a relatively higher average daily traffic volume.
Fifty-three percent of all reported accidents have been from
vehicles leaving the roadway or striking livestock. By contrast,
the SoRe 264 corridor average for these combined accidents is 40
percent. Eleven percent of the accidents were rear-end
collisions.
S.R. 264 seqment 5
Two-car collisions are more prominent on this 4.5 mile segment of
roadway near Window Rock where 2 out of 3 accidents involve two
vehicles. This is consistent with the relatively more urbanized
environment of Window Rock compared with other areas on the
corridor. The most frequent accident types are rear-end and angle
collisions. Each comprised 18 percent of the total number of
accidents 0 This too, is an indication of an urban environment
characterized by higher volumes of traffic and numerous access
points abutting the roadway. Surprisingly, animals struck on the
roadway account for 12 percent of the accidents.
37
Review of the 1988 Accident Rate SUfficiency system categorized
the area between mileposts 473.00 and 474.00 as being poor. This
rating in an urbanized area prompted a review of accident records
from 1986 through 1989 for segment 5. Over the 4-year study
period, 130 accidents resulting in 46 injuries and 9 fatalities
occurred on this 4.5 mile segment. These findings promoted
additional analysis of this segment. An analysis of accidents
occurring between mileposts 472.63 and 476.12 was selected due to
its status as a 4-lane roadway. Exhibit 17 illustrates the number
of accidents, injuries, and fatalities on both segment 5 (4.5
miles) and the 3.49 mile study section of 4-lane roadway. The
study section has approximately 94 percent of all accidents, about
96 percent of all injuries and 100 percent of the fatalities for
segment 5. In addition, the study section comprises 24 percent of
the accidents and 29 percent of the fatalities for the entire
corridor S.R. 264.
38
EXHIBIT 17
Hierarchical Accident Comparisons on Segment 5
1986 1987 1988 1989 Total ~
2-
Segment 5
M.P. 471.62 - 476.12
Accidents 36 35 36 23 130 100.0
Injuries 9 15 15 7 46 100.0
Fatalities 1 1 6 1 9 100.0
segment 5
M.P. 472.63 -
476.12
Accidents 32 33 34 23 122 93.8
Injuries 8 14 15 7 44 95.6
Fatalities 1 1 6 1 9 100.0
The CLOSE report compiled by the Traffic Studies Branch in May,
1990 focused on S.R. 264 between mileposts 473.66 and 473.77. The
CLOSE report found that many accidents recorded at milepost
473.66, the intersection of S.R. 264 and Indian Route 12 (south),
was in error; those accidents actually occurred at milepost
475.49, the intersection of S.R. 264 and Indian Route 12 (north).
Therefore the focus of the CLOSE findings deals with the north
intersection at milepost 475.49. The report cites that 30
accidents and 7 injuries were recorded between 1985 and 1988.
There were no fatalities. The CLOSE report recommended hardware
improvements to the signals including left turn phasing.
Exhibit 18 indicates there are several consistent contributing
factors to accidents in Window Rock. The two largest contributors
to accidents in this section involved intersections and driveways
accounting for 62 of the 134 total factor combinations. Intersec­tion-
related collisions were the largest contributing factor
involving 36 accidents and 26 driveway-related accidents. Most of
these--74 percent-were 2- and 3-car accidents. The majority of
these accidents were property damage only and did not involve
serious injuries or fatalities.
There is concern for the large number of accidents that cause
minor injuries and the economic costs associated with them. This
combined number of accidents involving intersections and driveways
is linked to the number of turnouts on and off of the highway.
The large percentage of mUltiple-car collisions also signifies the
extent of the contiguous built-up area in Window Rock and the need
to adjust to the more urbanized conditions.
39
EXHIBIT 18
ATTRIBUTING FACTORS TO ACCIDENTS ON S.R. 264
M.P. 472.63 - 476.12
Total
Total
Accidents" 32 33 34 23 . 122
Driveway
Access 12 4 7 3 26
Intersection 7 10 12 7 36
Alcohol 5 6 5 4 20
Pedestrian/
Pedalcyclists 1 2 4, ,... 8
Animals 3 5 2 2 12
Other"" 7 8 8 9 32
.. .... More than one factor may cause an accident. All other factors not identified in exhibit.
Records indicate that there were 8 pedestrian/pedalcyclist
accidents involving four fatalities.
Properties accessing the highway could contribute to the number of
accidents relating to driveway access. The area abutting the
highway has numerous driveways and streets which are frequently
offset. Unregulated access coupled with a large number of offset
streets abutting the highway right-of-way promotes traffic
conflict. A prescription for managing access on state highways is
currently being developed, however some steps could be taken by
the Chapter House and Tribal Council in the interim to help
mitigate the situation.
40
Proposed steps might include the following:
(1) eliminate unnecessary driveways;
(2) provide incentives to construct shared or common drive­ways;
(3) develop driveway guidelines-the spacing and realignment
of offset streets and driveways are needed to decrease
the amount of side friction;
(4) adopt a circulation plan; plan for future growth and
street system/evaluate site plans for accordance with
long range plan,
(5) provide for highway appurtenances to help direct traffic
(raised medians, curbing and sidewalks),
(6) include left-turn lanes, and;
(7) install decelerate lanes.
Additional information regarding the development of access
guidelines can be found in Appendix A and B.
Given the number of accidents and findings of this report it may
suggest that additional inspection of this highway might be
warranted in the future. If additional inspection is warranted,
it may justify additional traffic engineering studies to determine
if corrective steps are needed. Potential concepts to explore
are:
• Community Awareness Programs
• Access management
• Driveway guidelines
• Signalization/intersection improvements
• Curb, sidewalks, street lights
• Animal control enforcement
• R-O-W fence modifications
Many accidents are caused by operator error and in some cases
substance abuse. Design-related changes to the roadway will
probably not prevent these type of accidents.
As a prelude to the development of this report, intergovernmental
agency meetings were held to discuss joint highway issues between
state and tribal transportation officials. The subject of accident
reports was an issue discussed. Consensus was reached between
state and tribal officials that some accidents may go unreported;
41
furthermore, the inaccurate reporting of accidents could result in
insufficient statistical documentation. In conclusion consensus
was also reached to improve training for accident investigators
and to improve accident reporting procedures with ADOT.
During the course of accessing the historical accident database
for this corridor study, several difficulties were encountered by
this group of researchers. We recorded the following observa­tions:
Accident data tends to be reported either inaccurately or
with portions of data missing. Also, the reporting process tends
to be sporadic with accident reports reaching ADOT late. In
addition, Traffic Records Unit believes the reporting of accidents
has recently decreased. This lack of precision in data collection
and reporting may create difficulty in detecting potential
hazards.
consultations were conducted with Traffic Engineering Section
concerning the accuracy of data. Traffic Engineering is of the
opinion that in-depth investigation of accident reports be
completed prior to final selection of highway safety improvements.
Based on their experience, the types of problems encountered are:
1. Accidents are not properly located on the State Highway
System.
2. Accidents reported on the State Highway System are often
determined to have taken place on local roads or
driveways.
3. Not all of the accident reports are sent to ADOT.
42
POTENTIAL CORRIDOR NEEDS
The Department conducts an analysis of service, quality and
facility condition of the highway system to quantify the invest­ment
necessary to operate the system over the next ten year
planning period. The investment requirements are potential costs
and are not actual costs. Results from this analysis are useful
in establishing an aggregate picture of future corridor transpor­tation
actions and associated costs which can be evaluated and
refined with transportation engineering and implementation
programs.
The highway system analysis is based on the needs study analytic
model and the results are constrained by the reliability and
validity of the input data, by the assumptions built into the
model, and by the assumption that all other conditions remain
unchanged. The following discussion provides a conceptual
overview of this computer analytical process.
All highway links are grouped into one of five categories depend­ing
on the amount, type and purpose of travel found on each
highway. Each of the five categories has a specifically defined
set of planning design and performance standards. These planning
design and performance standards represent the ultimate level of
improvement or development which is desirable for a given highway.
They also define the condition to which pavement will be main­tained.
Please see Appendix F for definitions of the five catego­ries
and the associated planning design and performance standards.
In the corridor study area, u.s. 191, S.R. 87, and S.R. 264 are
Level of Development (LOD) 3 routes. LOD 1 routes are controlled­access
facilities, LOD 2 routes are the most important non­controlled
access routes statewide.
Routes without unique travel or service characteristics comprise
the Level of Development 3 category. Level of Development 3
routes are mainly two-lane rural routes with provisions for
passing lanes where needed. Most of the routes on the state
system are in this category. LOD 3 routes will have some major
reconstruction projects of limited length, will be on the pavement
preservation program, and will receive regular, routine mainte­nance.
ADOT's ongoing data collection efforts provide a current inventory
of system condition. For each corridor, the routes existing
condition has been analyzed to identify deficiencies as measured
against the planning design and performance standard. The identi­fied
deficiencies provide the basis for the analytic model to
identify the type of improvement projects needed to bring the
route up to the planning design and performance standards. The
analytic model then selects the appropriate remedy action given a
highway section which contains a combination of deficiencies.
Once the appropriate remedy action is assigned, the analytic model
then estimates improvement costs. Please see Appendix G for a
43
discussion on remedy actions. Exhibit 19 illustrates the cross­section
improvements identified by the analytic model (refer to
Appendix H). U.S. Route 191 has over 100 miles of cross-section
improvements identified or almost 77 percent of the corridor
length. State Route 87 has just over 44 miles of identified
improvement to the roadway cross-section and State Route 264 has a
minor amount of mileage identified.
EXHIBIT 19
ANALYTIC MODEL
POTENTIAL ROADWAY CROSS-SECTION IMPROVEMENTS
ROUTE
NUMBER
U.S. 191
S.R. 87
S.R. 264
IMPROVEMENT
TYPE
Resurface Roadway
Reconstruction
Resurface Roadway
Resurface Roadway
Resurface Roadway
Resurface Roadway
Resurface Roadway
Resurface Roadway
MILEPOSTS
11.12-37.63
51.00-51.26
51.26-72.82
74.68-103.90
108.00-130.61
346.34-346.68
361. 82-406.04
388.45-388.79
Structural deficiencies involve bridges, grade separations, and
other structure's which carry traffic or which cross the roadway.
Those structures that do not meet current design standards are
classified as functionally obsolete. Bridge sufficiency is a
composite rating based on a structure's deficiencies in relation­ship
to the structure's use, and is indicative of sUfficiency to
remain in service. ADOT rates the sUfficiency of its bridges and
other structures on a scale of 1-100. ADOT assign? priority among
structural improvements solely on the basis of sUfficiency
ratings.
Using bridge sUfficiency ratings to prioritize improvements, ADOT
channels funds toward replacing structures with the lowest
sufficiency ratings. Bridges with sufficiency ratings below 50
are considered first. Then, depending on funding, structures with
sUfficiency ratings between 50-80 receive attention. Exhibit 20
illustrates the bridge structure improvements identified by the
analytic model (refer to Appendix H). U.S. Route 191 has three
locations noted. S.R. 87 does not have any and S.R. 264 has ten
structured locations identified.
The ADOT structures database is continuously updated to provide a
current inventory and appraisal of all structures on the State
Highway System. The bridge sUfficiency ratings contained in the
database provided the means to identify deficient structures. The
assessment of improvement costs involved manipulating the informa­tion
contained in that database to determine the replacement cost
of deficient structures.
44
EXHIBIT 20
ANALYTIC MODEL
POTENTIAL STRUCTURE IMPROVEMENTS
ROUTE
NUMBER
U.S. 191
S.R. 87
S.R. 264
MILEPOST
LOCATION
69.29
96.02
102.34
None Identified
324.10
362.65
387.30
387.94
400.60
408.54
418.55
419.30
446.20
451.30
ADOT's pavement preservation program is designed to maintain the
State Highway System at established levels of pavement condition
from year-to-year. Each year every mile of the State Highway
System is surveyed for evidence of pavement deterioration. Two
measures are used to assess pavement condition: ride roughness and
the percentage of surface cracking.
In 1980, sets of pavement condition standards were established for
major categories of roadways. For a given roadway classification,
the standards set a minimum allowable percentage pf mileage with
pavement in satisfactory condition, and a maximum allowable
percentage of mileage in objectionable condition.
ADOT's Pavement Management System computer model was used to
forecast the costs needed to maintain pavement to standards in the
coming five (5) years. Results from this computer model were used
as the basis to arrive at a statewide, non-interstate annual
average cost per mile. This statewide unit cost factor was
utilized to estimate pavement preservation costs for the ten year
corridor planning period (refer to Appendix I).
To complete the picture of anticipated corridor costs, routine
maintenance activities should be considered in the estimate of
future costs. For each corridor historical routine maintenance
costs have been collected during a three year period to calculate
the average cost-per-mile. This cost data is illustrated in
Appendix J. The corridor specific annual average unit cost factor
was utilized to estimate routine maintenance costs for the ten
year corridor planning period.
45
with the delineation of system service and quality completed the
associated corridor investment requirements can be estimated.
Potential investment requirements estimated under the level of
development concept are quantified in Exhibit 21. The potential
investment requirement for the corridors of U.S. 191, S.R. 87, and
S.R. 264 is $52,937,000 during the next ten year planning period.
Improvements to the roadway on U.S. 191 are the single largest
investment by type of improvement for any corridor. On S.R. 87,
roadway improvements are the single largest investment requirement
by type of improvement. On S.R 264, routine maintenance is the
major investment requirement. U.S. 191 has a potential corridor
investment requirement of $26,642,000 or approximately 50 percent
of the grand total for all three corridors.
The amount estimated is reasonable if the planning design and
performance standards are to be met during the next ten year
planning period. Capital investment requirements have significant
impact upon system operational decisions. Aggregate actual costs
may ultimately be higher than the potential investment require­ments.
These improvement actions and associated costs are based
on transportation planning and are not based on preliminary
highway engineering. Further evaluation and refinement is neces­sary
to identify specific improvement design and its associated
cost.
EXHIBIT 21
LEVEL OF DEVELOPMENT CONCEPT
1991-2000 POTENTIAL CORRIDOR INVESTMENT REQUIREMENTS
($1,000 1988 Prices)*
IMPROVEMENT CORRIDOR
TYPE US 191 SR 87 SR 264 TOTALS
Roadway 13,237 3,408 36 16,681
Structure 1,289 -0- 1,595 2,884
Pavement
Preservation 6,294 2,925 7,456 16,675
Routine
Maintenance 5,822 1,504 9,371 16,697
TOTAL $26,642 $7,837 $18,458 $52,937
* Rounded
46
CORRIDOR SUFFICIENCY RATINGS
The ADOT Sufficiency Rating System is a tool for evaluating and
reporting information on the condition and performance of the
State Highway System. It is a composite measure of condition,
safety and service considerations for each mile of the State
Highway System. The sUfficiency rating system:
• measures the extent to which state highway segments meet
system objectives and standards; and
• assists in the project programming process by providing an
improved means of assembling the need for improving one
highway segment relative to other highway segments.
Each of the three components of the sUfficiency rating are
measured by two roadway characteristics. The condition of the
system is evaluated by Pavement Life and Pavement Rut Depth.
Accident Rate and Severity Rate are the two measurements of
safety. Service is measured by Current Daily Traffic Per Lane and
Future Daily Traffic Per Lane. Definitions of the six roadway
characteristics are as follows:
1. Pavement Life is the number of years before some remedi­al
action will be required. It is a prediction based
upon the rate of change in pavement roughness and
cracking.
2. Pavement Rut Depth measures the depth
rutting in inches. This information
available for Interstate routes only.
of
is
pavement
currently
3. Accident Rate is the number of accidents per million
vehicle miles of travel over the three most recent
years.
4. Severity Rate is a weighted accident rate in which fatal
accidents, injury accidents and property damage acci­dents
are assigned weights of three, two and one,
respectively.
5. Current Daily Traffic Per Lane is the most recent
average daily traffic count or estimate divided by the
number of roadway lanes.
6. Future Daily Traffic Per Lane is the twenty-five year
forecast of average daily traffic volume divided by the
existing number of roadway lanes.
For every mile of the State Highway System, a good, fair, and poor
rating is assigned for each of the six roadway characteristics.
47
The ratings describe how the condition and performance for anyone
roadway segment. compare with those of other roadway segments on
the state Highway System. The sufficiency ratings are relative:
good is better than fair; fair is better than poor.
The ratings are assigned using "sufficiency rating standards" for
each of the six criteria. Roadway operating and performance
characteristics are different for freeway and arterial highways.
Consequently, different sUfficiency rating standards are used for
different Levels of Development (LOD). The Level of Development
(LOD) concept orders state routes or route segments within a
hierarchical system. There are five levels to which a route or
portion of a route can be assigned, depending on its use and
function within the State Highway System. The highest LOD is LOD
I, or Interstates and Urban controlled-access facilities, while
the lowest is LOD 5, or routes that no longer serve a statewide
function.
Because the assignment of a highway to a particular level of
development is standards-based, a highway will be reassigned to
another level of development, if the function and use of that
highway changes.
Operating and performance characteristics vary between urban and
rural highways as well. As a result, the sUfficiency rating
standards used also vary for large urban areas (over 50,000
population), small urban areas (over 5,000) and rural areas.
The sUfficiency rating standards that define good, fair, and poor
ratings were selected to provide meaningful and useful informa­tion.
The rationale used to select the standards for each of the
six roadway characteristics is as follows:
Pavement Life - ADOT uses a five year programming cycle to
schedule improvement proj ects. Roadway segments with a
projected remaining pavement life of five y~ars or less are
rated poor to identify them as candidates for improvement.
Roadway segments with a remaining life of eleven years or
more are rated good.
• Pavement Rut Depth - Pavement rut depth of 1/2" or more is
considered to be an indication of a structural problem and
will require immediate action. Pavement rut depth of 1/4" or
less is considered insignificant and is rated good (this
information is currently available only for Interstate
routes) .
Accident Rate and Severity Rate These standards were
defined in such a way that a specified percentage of the
roadway mileage is placed in each rating category. The 50%
of State Highway System mileage having the lowest accident
and severity rates is rated as good. The 10% of State
Highway System mileage with the highest accident and severity
rates is rated as poor.
48
Current and Future Daily Traffic Per Lane - These standards
generally correspond to service volumes for different levels
of service. Any roadways operating at levels of service A or
B are rated good. Urban roadways operating at level of
service E and rural roadways operating at levels of service D
or E are rated poor.
In addition to the ratings for each of the six conditions and
performance characteristics, a composite or weighted average
sUfficiency rating is computed for each mile of the state Highway
System. Condition, safety and service are considered to be
equally important and are given equal weight in computing the
composite sUfficiency rating. Likewise, the two measures of
roadway safety (accident and severity rates) and the two measures
of traffic congestion (current and future daily traffic per lane)
are considered equally important and are given equal weights.
However, the two measures of condition are not considered equally
important in computing the composite sufficiency rating. For LOD
1 (Interstates), pavement life is given twice the weight of
pavement rut depth. For urban controlled-access highways in LOD 1
and all roadway segments in LOD 2 and LOD 3, information describ­ing
pavement rutting is unavailable and pavement life alone is the
sole determinant of the condition rating and is assigned a weight
equal to the combined weight of the two safety measures or the two
service measures.
One significant problem in dealing with averages is that extreme
input values, whether good or poor, can be hidden in the final
calculation. A roadway segment with a fair composite SUfficiency
rating could have poor ratings for two or three of its condition
and service characteristics. The SUfficiency Rating System
addresses this problem by computing a "deficiency factor" for each
roadway segment.
The deficiency factor ignores good and fair SUffIciency ratings
and focuses on poor ratings. It is a number that ranges from zero
to six. For a short highway section, the deficiency factor is
simply a count of the number of characteristics with a poor
SUfficiency rating. When SUfficiency ratings are desired for more
lengthy highway sections, project boundaries or entire routes, the
SUfficiency Rating System reports distance weighted average values
for all roadway characteristics and SUfficiency ratings, and for
the deficiency factor. Under any of these circumstances, the
deficiency factor can be interpreted as follows:
• a value of zero means that there are no poor SUfficiency
ratings in any of the roadway systems evaluated;
a value of six means that all six roadway characteristics
have a poor SUfficiency rating;
a value higher than zero but lower than six means that there
are poor SUfficiency ratings for some but not all of the
characteristics evaluated.
49
Using the most current (1988) data available, the number and
percentage of route miles which fall into the poor ratings
category for five of the six roadway characteristics were calcu­lated,
as were the overall sUfficiency rating and the deficiency
factor. Pavement rutting is not included since data is available
only for Interstate routes. These calculations are useful in
evaluating the performance of u.s. 191, S.R. 87, and S.R. 264.
Exhibits 23 through 36 show where the corridor routes rate as poor
for each sUfficiency rating category. Appendix K contains each
corridor rating for deficiency factors.
The following explanations are provided in an effort to prevent
misinterpretation of data presented in this document. As a result
of systemwide management parameters, the identified corridor needs
may not be of sufficient priority on a statewide basis in meeting
defined condition standards and therefore to qualify for a portion
of the limited funding available.
This report used the most current data available, which was the
year 1988, No adjustment has~been made to the percentages of good,
fair, and poor categories when roadway sections may have been
improved since the (1988) data was collected. Furthermore, no
adjustments have been made to roadway sections which are already
scheduled for improvement.
The SUfficiency Rating System is a tool to help guide planning and
programming decisions. A comparison can be made of Exhibits 22
through 35 with the areas identified for short and long range
improvements.
50
x
(")
o
POOR
<i9if. z o ~.Round Rock f'T'1
Many r :E
Farms •
A plA C H E ~
,.chinle
"
25
/,I
I
I
NAVAJO/' Tuba.Ci1y
• Moenkopi i. !
Coal IMine Mesa I
g H"\. Polacca Keams I'
CI I .. -~Yon ioralbi~Seam ..J.~St_ea.:...m8b~oat ...,..-- "Fi~~~w
I Nissa L 6-4 / -I
i Saba ~la.gel0h
I Delkaje Q •
~ § .Wlde Ruin
_ r1ilknn j -.- ~ c;be~rsl
8
o
® Page
EXHIBIT 22
1988 PAVEMENT LIFE SUFFICIENCY
UTA H
MILES
Exhibit 22 shows the sections of u.s. 191, S.R. 87 and S.R. 264
that are rated poor for pavement life. Approximately 34% of u.s.
191 corridor mileage is rated poor, with the majority of poor
rating located near Chinle, Many Farms and Rock Point. Of the
three corridor routes, S.R. 87 has the least amount of poor rating
(30.5%). In contrast, large sections of S.R. 264 are rated
poorly, consisting of 52.6% of S.R. 264 corridor mileage. The
settlements of Moenkopi, Coal Mine Mesa, oraib{, Second Mesa,
Keams Canyon, Polacca, Steamboat, and Window Rock are near the
poorly rated pavement sections.
EXHIBIT 23
Pavement Life SUfficiency Ratings
Good Fair Poor
U. S. 191 Miles 68.64 17.00 44.00
Percent 53.0% 13.1% 33.9%
S.R. 87 Miles 31. 00 11.00 18.47
Percent 51. 3% 18.2% 30.5%
S.R. 264 Miles 47.00 26.00 81.15
Percent 30.5% 16.9% 52.6%
51
EXHIBIT 24
1988 ACCIDENT RATE SUFFICIENCY
UTA H
8 Page
Tase
Nos Pos
8 I §$<~"
I z
® .Round Rock
rrI
§ I Many - :E
I Farms .~
PIA 3:
N A V A J 01 A c H E
Tuba.City '" rrI • Chinle
• Moenkopi j I x
8 Coal IMine Mesa I (") . Cameron 8 0
~'".'''
Jeupp 8 (§ ·.Wide Ruin
DHkon
Flagstaff 8 . 8 Chambers ~
~
@ Sanders
8
8
a 25 50
MILES
This is an alternative and complimentary method to the comparing
and contrasting of historical accident data presented in earlier
sections of this document. U.S. 191 has both the most mileage and
highest percentage of mileage rated poor for any of the three
corridors under study (see Exhibit 24). The settlements of Chinle
and Many Farms are the most impacted. S.R. 87 fares much better,
with only 0.7% or .43 of a mile rated poor near the junction of
Interstate 40. S.R. 264 has 2.6% of its mileage rated poor near
the junctions of U.S. 191 and near Window Rock. In fact, a
significant percentage (76.1%) is rated good for S.R. 264.
EXHIBIT 25
Accident Rate SUfficiency Ratings
Good Fair Poor
U.S. 191 Miles 49.20 68.00 12.44
Percent 38.0% 52.4% 9.6%
S.R. 87 Miles 39.04 21.00 0.43
Percent 64.6% 34.7% 0.7%
S .R. 264 Miles 117.24 32.91 4.00
Percent 76.1% 21. 3% 2.6%
52
8 z
Round Rock ,..,
:::
C H E :s:::
,..,
X
(')
0
Window
Rock
ChI'afilm1berXs ~san~ders"
'J
I
I
I
I
Oi
I
I
• Oraibi
• Moenkopi i
Coal ,Mine Mas a •
Cameron 8••
® Page
a
®
§
Tuba.City N A V A J
8
EXHIBIT 26
1988 ACCIDENT SEVERITY SUFFICIENCY
UTA H
o 25 50 POOR
MILES
Of the three routes, U.S. 191 contains the largest number of miles
rated poor by the severity rate. A total of 9.4 miles, or seven
percent of the route is rated poor as shown in Exhibit 27. One­third
of this poorly rated mileage is situated on a 3-mile stretch
of roadway between mileposts 73.00 and 76.00 near Chinle. The
remaining sections rated poorly are I-mile sections located
sporadically on the route. only 4 miles of roadway on S.R. 264 is
rated poor; two miles are located between mileposts 439.00 and
441.00, and one mile is located at milepost 473.00 in Window Rock.
EXHIBIT 27
Severity Rate SUfficiency Ratings
Good Fair Poor
U.S. 191 Miles 48.20 72.00 9.44
Percent 37.2% 55.5% 7.3%
S.R. 87 Miles 45.04 15.00 0.43
Percent 74.5% 24.8% 0.7%
S .R. 264 Miles 115.61 34.54 4.00
Percent 75.0% 22.4% 2.6%
53
.Klageloh
--POOR 50
Leupp
25
MILES
0 I Farms •
;::
N A V A J oj A C H E
Tuba .City ".,
• Chinle
• Moenkopi i I x
8 Coal tMine Mesa I () . Cameron 8 0
o
Exhibit 29 indicates that on S.R. 264, 15 percent or 23.63 miles
are rated as poor. However, despite this poor designation, the
entire 23.63 miles is not a problem area; the actual mileage rated
poor is significantly less. The inflated rating_ is due to the
location of the traffic count: in Window Rock. The data contained
in the Traffic Analysis section of this report is a more accurate
representation of traffic.
EXHIBIT 29
Current ADT SUfficiency Ratings
Good Fair Poor
u.S. 191 Miles 128.64 1. 00 0.00
Percent 99.3% 0.7% 0.0%
S .R. 87 Miles 60.47 0.00 0.00
Percent 100.0% 0.0% 0.0%
S .R. 264 Miles 128.22 2.30 23.63
Percent 83.2% 1. 5% 15.3%
54
Sanders
8
POOR
8 .Wide Ruin
Chambers
Dilkon . 6
50
Leupp
8
25
EXHIBIT 30
1988 FUTURE DAILY TRAFFIC
PER LANE SUFFICIENCY
UTA H
8 Page 8 (
8 8 Kaye8nta) I
I 8 z
@] Round Rock • ,..,
l§l I Many :::E
I Farms •
3:
N A V A J 01 A p A C H E
Tuba City . ,.., • Chinle
• MoenkopI I I X
8 Coal IMine Mesa • I (") Cameron 8
,
. 0 Poiacca ~:;;6~1
Oralbi I Stea.mboat
o
MILES
As seen from Exhibit 31, both u.s. 191 and S.R. 87 have good
ratings for nearly 100 percent of the routes. Only S.R. 264 has
some mileage rated as poor. Given this rating, further analysis
was conducted on this 23. 63-mile section of roadway. The data
contained in the Traffic Analysis section of this report reflects
a more accurate analysis of traffic. The actual mileage with a
poor rating is much less than indicated in Exhibit 31 and is
generally located in the Ganado and Window Rock areas.
EXHIBIT 31
Future ADT SUfficiency Ratings
Good Fair Poor
u.S. 191 Miles 128.64 1.00 0.00
Percent 99.3% 0.7% 0.0%
S.R. 87 Miles 60.47 0.00 0.00
Percent 100.0% 0.0% 0.0%
S.R. 264 Miles 122.62 7.90 23.63
Percent 79.6% 5.1% 15.3%
55
® Page
Flagstaff
~
EXHIBIT 32
1988 DEFICIENCIES
UTA H 8 Mex!can Water
S Teec • 8
Kayenta Nos Pos
8 8, , ~ "~OCk Po,nt
8 II
e~ .. z
M.~ ~.~~"-" ,."
8 I :;:
I Farms
;::
N A V A J oi A p ~c~nleH E ,."
I x 0 25 60
I (") MILES
0
o DEFICIENCIES
1 TO 2 DEFICIENCIES
3 TO 6 DEFICIENCIES
As seen from Exhibits 32 and 33, U.S. 191 contains 3 miles of
roadway found .to be rated poor by deficiency factors. Roadways
are given a poor rating if the section has 3 to 6 factors that are
found to be deficient. These locations--all in segment 2--are
between mileposts 74.00 and 75.00, 76.00 and 77.00, an area in or
near Chinle and between 91.00 and 92.00, an area north of Many
Farms. S.R. 87 does not havE~ any sections of roadway considered
as poor. Segment 5 on S.R. 264 does have 1.63 miles of roadway
considered as poor near Window Rock. These sectlons of roadway
are between mileposts 472.00 and 472.63 and between mileposts
473.00 and 474.00.
EXHIBIT 33
Deficiency Factor Ratings
Good Fair Poor
U.S. 191 Miles 76.20 50.44 3.00
Percent 58.8% 38.9% 2.3%
S.R. 87 Miles 42.00 18.47 0.00
Percent 69.5% 30.5% 0.0%
S .R. 264 Miles 47.03 105.49 1. 63
Percent 30.5% 68.4% 1.1%
56
EXHIBIT 34
()
o
z
1'1
><
E
,
I
I
I
I
NAVA,IOj
I
I
8
COMPOSITE SUFFICIENCIES
UTA H
8'--,. Page
§l I
Leupp
Flagstaff
~
~
8
8
0 25 50
MILES FAIR
GOOD
As seen from Exhibit 35, U. S. 191 and S. R. 87 do not have any
mileage rated poor based on the composite sUffici~ncy. The only
blemish on S. R. 264 comes from a poor rating on segment 5 near
Window Rock. Although only .63 of a mile in length, this section
did have a large number of accidents that was confirmed by
accident reports.
EXHIBIT 35
Composite SUfficiency Ratings
Good Fair Poor
u.S. 191 Miles 65.20 64.44 0.00
Percent 50.3% 49.7% 0.00%
S.R. 87 Miles 37.00 23.47 0.00
Percent 61.2% 38.8% 0.0%
S. R. 264 Miles 36.25 117.27 0.63
Percent 23.5% 76.0% 0.4%
57
TRAFFIC ANALYSIS OF CORRIDOR ROUTES
AVERAGE DAILY TRAFFIC
Average daily traffic (ADT) measures the amount of vehicles per
day that traverse a given roadway. When used in relation to the
roadway's design capacity, it is a useful tool in evaluating the
present and future ability of' a roadway to carry traffic. For
this corridor study, ADT data for U.S. 191, S.R. 87, and S.R. 264
from 1975 to 1988 is from Tra:ffic on the Arizona Highway System,
published annually by the ADOT Travel and Facilities section; this
section also has developed forecasts through 2010 for each of the
corridor routes. Historical data for U.S. 191 prior to 1980 is
not available.
EXHIBIT 36
Actual and Projected ADT
S.R. 264, U.S. 191, and S.R. 87
ADT (thousands)
7 .
Estimate
6
5
4
3
2
1
Projection
,...U.S.191
'-S.A. 87
1975 1980 1985 1990 1995
Year
2000 2005 2010
Sources: Estimates - Traffic on the
Arizona Highway System, 1975-1988, ADOT;
Projections - ADOT Travel and Facilities
58
u.s. 191
Exhibit 36 shows estimated and pro:jected ADT for each corridor
route in its entirety within the study area. Traffic on the
entirety of u.s. 191 in the corridor study area increased from 820
in 1980 to 1,376 in 1988. It is projected that traffic will
increase to 1,816 or nearly 32%, by the year 2010. When analyzed
by segments, Segment 2, which is north of S. R. 264, has had a
higher ADT since 1980 (see Exhibit 37). This trend is expected to
continue. Overall, traffic is and will remain much lighter on
u.S. 191 compared to S.R. 264.
EXHIBIT 37
Actual and Projected ADT
U.S. 191
ADT (thousands)
2.5 Estl.mates
2
Projections
1.5
1 r -
,"--Segment 2
'--- Segment 1
0.5
1980 1985 1990 1995
Year
2000 2005 2010
Sources: Estimates - Traffic on the
Arizona Highway System,1975-1988, ADOT;
Projections - ADOT Travel and Facilities
S.R. 87
Of the three corridor study routes, S.R. 87 carries the least
amount of traffic daily (see Exhibit 36). Although traffic has
grown steadily from 1983 to 1988, there has been considerable
oscillation in annual ADT since 1975 (see Exhibit 38). Traffic is
expected to increase by 52% by 2010, equal to approximately 400
more vehicles per day. This corridor route is proj ected to
continue carrying the least amount of traffic.
59
EXHIBIT 38
Actual and Projected ADT
S.R.87
ADT (thousands)
1.4 Estimate
1.2
0.4
0.2
Projection
I , iii Iii iii iii,
1975 1980 1985 1990 1995
Year
2000 2005 2010
S.R. 264
Source8: E8t1mate - Traffic on the
Arizona Highway System. 1975-1988, "DOT;
Projection' "DOT Travel and Facilities
In 1988, the average daily traffic (ADT) on S.R. 264 was 2,589 for
the entire route (see Exhibit 36). By the year 2010, traffic is
projected to average 6,190 for the entire route, an increase of
approximately 139 percent. Traffic on this route is by far the
greatest of the three corridor routes. In Exhibit 39, the ADT for
each of the five study segments of S.R. 264 is presented.
EXHIBIT 39
Actual and Projected ADT
S.R.264
ADT (thousands)
30 Est'Imates
25
20
15
10
Projections
1975 1980 1985 1990 1995
Year
2000 2005 2010
Source8: Estlmate8 - Traffic on the
Arizona Highway System, 1975-1988, "DOT;
Projections - "DOT Travel and Facliitiea
60
ADT is highly variable from segment to segment, reflecting the
degree of urbanization and local traffic in the area. Segments 3
and 5 by far have the highest ADT in 1988. These segments are
located in the Ganado and Window Rock areas, respectively.
Segments 1 and 2, with the lowest ADT, are long rural stretches
from Tuba city toward Ganado. By 2010, disparities in ADT between
the segments will be amplified, ranging from 4,206 in Segment 2 to
24,889 for Segment 5.
The Transportation Research Board has developed design capacity
criteria for urban fringe and rural area roadways2, which is
applicable to the corridor study area. According to this criteria,
the maximum ADT that a two lane rural highway can carry is 9,000,
and the maximum that a four-lane rural highway can carry is
18,000, to achieve at least Level of Service "c" (LOS). Level of
Service is a qualitative measure of operating conditions, ranging
from LOS "A", the best operating conditions, to LOS "F", which is
the worst. In urban fringe and rural areas, LOS "D" or lower is
usually considered unacceptable. If 'traffic volume exceeds the LOS
"C" standard without access control, motorists will probably
encounter difficulties in turning on and off the roadway, limiting
their ability to change lanes, pass, or travel at preferred speed.
Without access control, a four lane roadway likely will be needed
to carry traffic higher than 9,000 ADT to ensure satisfactory
operating conditions.
All three corridor routes are predominantly two lane rural
roadways, meeting the Transportation Research Board's design
criteria. By examining Exhibits 36-39, it is apparent that only
some segments of S.R. 264 have the potential to have traffic
exceed the 9,000 ADT standard by the year 2010. More specific­ally,
Segment 5 has exceeded the st:andard since 1986, Segment 3
could do so in 1990, while Segment 4 is projected to exceed the
standard in the year 2004.
Although the three corridor routes are predomin"antly two lane
roadways, there are some four-lane sections. U.S. 191 near Chinle,
between mileposts 73.22 to 74.31, which is equal to 1.09 miles,
has four travel lanes. S.R. 264 near Polacca between mile-posts
403.02 and 403.41 is another location that has four travel lanes.
Also on S.R. 264, a stretch of four-lane roadway exists from the
st. Michaels area, starting at milepost 472.63, to the New Mexico
state line, or milepost 476.12, a distance of 3.49 miles. By
examining Exhibit 39, it is apparent that two segments of S.R. 264
have the potential of having traffic exceed the 18,000 ADT
standard by the year 2010. Segment 5. could exceed the standard by
the year 2002, while Segment 3 may exceed the standard in the year
2008, based on current projections.
2 Highway Capacity Manual, Special Report 209,
Transportation Research Board, National Research Council,
Washington D.C., 1985, pp. 8-14.
61
LAND USE
As the principal mode of transportation for goods and people in
Arizona the highway system is the essential element that provides
accessibility to all areas of the state. Highways directly impact
their immediate environment through their effect on adjacent land
use. without an adequate highway system, it is difficult to
attract and maintain economic activity.
The function of these highway:s is to serve a substantial volume of
traffic traveling at relatively high speeds on medium to long��distance
trips. The combination of this travel demand with the
travel demand of small urban and rural communities frequently
results in development along the highway wanting direct access.
In time, the proliferation of access points to the highway reduces
travel time and safety. This degradation of the capital invest­ment
frequently results in requests to improve travel time and
safety. The available options to enhance travel time and safety
include widening the roadway, relocation of the roadway or
transportation system management (TSM) actions.
The use of TSM actions can avoid the traditional approach which
requires large sums of monE~y to improve roadway capacity and
safety. Perhaps, a less costly alternative approach to protect
the facility is by controlling highway access. Currently, Arizona
does not have an effective highway access management program.
The Arizona Constitution guarantees every owner of property
abutting on a pUblic highway access to that highway. However,
only reasonable access, not direct access, to the highway is
guaranteed to property owners. Direct access to a highway is
highly desirable to commercial interests. Property owners seeking
an encroachment permit are assured of direct access, provided
access meets local ordinances, does not pose an immediate safety
hazard, and conforms to ADOT construction standards. Without any
statewide pUblic policy regulating the impacts -- due to system
access, ADOT's ability to preserve the financial investment in the
facility is impaired.
Due to the unique status of Indian lands, ADOT encounters a
difficult environment concerning access management of it's
highway. Congress and the U. S. court system has established
Indian land as a dependent sovereign nation. Conflicts in
administrative rules and policies, and regulatory authority hamper
normal operational aspects of state routes due to the unique
sovereign status of Indian land.
Additional research is needed to accurately compare the impacts of
direct access driveways upon highway capacity, safety, and capital
investment, with the impac1:s of access control upon highway
capacity, safety, and capital investment. Furthermore, case law
research is needed on: property rights, eminent domain, direct and
reasonable access, land use and access controls. It would be most
useful if this research could result in a published report which
would facilitate pUblic debate of the issues. To ensure
62
transportation objectives are
policy to increase emphasis
transportation planning. This
use and investment decisions.
achieved, it is now U. S. DOT IS
on integrating state and local
includes efforts to coordinate land
The federal government agencies including but not limited to the
Bureau of Indian Affairs, Department: of Health and Human Services,
and Housing and Urban Development should work with ADOT to develop
policies procedures, regulations and statutes concerning access
management of state highways through Indian land. Implementation
of enhanced access management will require more emphasis from both
State and Federal Government. ADOT should work with tribal and
local governments, the private se~ctor and the legislature to
develop policies, procedures, regulations and statues concerning
access control.
SOCIO-ECONOMIC ENVIRONMENT
Three counties, Apache, coconino, and Navajo and two reservations,
the Navajo Nation and the Hopi, are within the U.S. 191, S.R. 264
and S.R. 87 study area.
The counties, reservations, and communities in proximity to the
corridor routes have been analyzed for population trends from 1980
to 2010. An analysis of past and future population trends
provides an indication of what effects population has and will
have on highway demand. Population demographic changes in the
driving age population, will affect: the number of vehicles using
highways in the corridor study area.
Population estimates from 1980 to 1988 are provided by the
Department of Economic Security, except for the reservations and
their communities. In this case, sufficient housing unit data was
not available. Thus, data for the reservations and their communi­ties
for this time period are unofficial projections provided by
the Northern Arizona Council of Governments. All projections from
1989 to 2010 are provided by the Department of Economic Security.
63
EXHIBIT 40
Population of Apache, Coconino,
and Navajo Counties
19BO-2010
Population (thousands)
160 r;:::========::;-----
Eatlmate
.• - •• - Projection
140
120 Coconino County -......,.. Navajo County
It" . .---
----------- ----------
--- ---
---
100
80 . --
-~ --
---
..-_...-­---
"APache County
60
1995 2000 2005 2010
Year
1985 1990
40 f-l---L-L--l.--+-..L-L...l---L-+---l.--L-.J._1....-1---L--L-L.-L-+-.L-....l---l..----L.-+---l-..L-.l.-...JL..-.j
1980
Source: Estimatea and Projections ­Department
of Economic Security, 2/90
Exhibit 40 shows the population estimates and projections for each
of the three counties. All three counties have experienced marked
growth from 1980 to 1988, with Coconino County, the most populous,
growing the fastest rate, a.t over 24%. Growth has also been
strong in Apache County, at nearly 22%. Navajo County has had the
slowest growth, at just under 15%. Overall, the combined popula­tion
growth for all three counties since 1980 is estimated to be
approximately 39,000. From 1988 through 2010, the average annual
growth rates for Apache and Coconino Counties is expected to
decline slightly, with the opposite true for Navajo County. All
three counties are projected to have a population over 100,000 by
the year 2010, ranging from 102,600 in Apache County to 154,400 in
Coconino County.
64
EXHIBIT 41
Population of the Navajo Nation
1980-2010
--- -.... -- - _... --- -' -
.--
Population (thousands)
160.------------------------------,
140
120
100
801-·=--­60
40
20
1980 1985 1990 1995
Year
2000 2005 2010
-- 1980-1989 Projection .. --- 1990-2010 Projection
Sources: 1980-1989 Projections - NACOG;
1990-2010 Projections - Department of
Economic Security, February 1990
Exhibits 41 and 42 show the population growth of the Navajo Nation
and the Hope Reservation. From 1980 to 1988 the Navajo Nation has
seen rapid growth, at over 26%, a 2.9% average annual rate of
growth (see Exhibit 41). It is projected that nearly 50, 000
additional persons will reside in the Navajo Nation by 2010.
65
EXHIBIT 42
Population at Hopi Reservation
1980-2010
Population (thousands)
10,--------------'---------------_-.- ---, .......-... _. ..-......
8
6
4
2
-.,- ... ---
... _...... ... ... ....
1980 1985 1990 1995
Year
2000 2005 2010
-- 1980-1989 Projection ----- 1990-2010 Projection
Source.: 1980-'1989 ProJection. - NACOO;
1990-2010 ProJection. - Department of
Economic Security. February 1990
In contrast to the Navajo Nation, the Hopi Reservation has had
negligible growth from 1980 to 1988 (see Exhibit 42). However, it
is projected that the reservation will grow by over 40% from 1988
to 2010 to a population of 9,700, representing an average annual
growth rate of 1.6%.
66
The population trends of seven communities along or near the
corridor routes are shown in Exhibits 43-49. These communities
are in proximity to the corridor routes as follows:
S.R. 264 - Fort Defiance, Window Rock, and Tuba city
U.S. 191 - Chinle and Many Fanns
S.R. 87 - Dilkon and Winslow
While there are many other communi1:ies that are affected by the
corridor routes, only these communities have population data
available from the Department of Economic Security.
EXHIBIT 43
Population of Fort Defiance
1980·-2010
.. - 6
4
2
Population (thousands)
8,------------------
1980 1985 1990 19~~5
Year
2000 2005 2010
-- 1980-1989 Projection .- .. - 1990-2010 Projection
Sources: 1980-1989 ProJecltlon. - NACOG;
1990-2010 ProJection. - Department of
Economic Securltlf. February 1990
67
Exhibits 43-45 include the three communities in proximity to S.R.
264. Fort Defiance has grown by over 25% from 1980 to 1988 (see
Exhibit 43). Rapid growth is expected to continue at an unabated
pace through the year 2010, whE~n the community is proj ected to
have a population approaching 7,400.
EXHIBIT 44
Population of Window Rock
19BO-2010
Population (thousands)
5,---------------
4 ..'
.' -
3
2
1
1980 1985 1990 1~~95
'Year
2000 2005 2010
-- 1980-1989 Projection --- -- 1990-2010 Projection
Source.: 1980-1989 ProJection. - NACOG;
1990-2010 Prc)Jection. - Department of
Economic Siecurlty. February 1990
Near Ft. Defiance is the Navajo Tribal Headquarters of Window Rock
(see Exhibit 44). Window Rock has had and is projected to have
similar growth rates as its neighbor, and have a population of
over 4,800 to 2010. Indeed, thE~se two communities are expected to
be the fastest growing of the seven.
68
EXHIBIT 45
Population of "Tuba City
1980-,2010
Population (thousands)
12,----------------
10
8
6
4
2
-' '* ..
~--
---
1980 1985 1990 1995
Yea,r
2000 2005 2010
-- 1980-1989 Projection ---"'- 1990-2010 Projection
Source.: 1980-1989 Pr,oJectiona - NACOG;
1990-2010 ProJectionl. - Department of
Economic Security" February 1990
Tuba city rests at the opposite end of S.R. 264 (see Exhibit
It is the largest of the communities on the reservation,
should remain so by the year 2010, nearing 10,000 persons at
time.
69
45) .
and
that
EXHIBIT 46
Population of Chinle
19180-2010
Population (thousands)
6.--------------
5 .-.- --
4
2
1
-" --
1980 1985 1990 1!~95
'Year
2000 2005 2010
-- 1980-1989 Projection - ---- 1990-2010 Projection
Sourcu: 1980-1989 ProJection. - NACOG;
1990-2010 ProJection. - Department of
Economic S.ecurlty. February 1990
Exhibits 46 and 47 include the~ two communities in proximity to
U.S. 191. Chinle has grown at an average annual rate of 2.5% from
1980 to 1988, and is projected to grow at a slightly lower rate,
2.1%, through 2010 (see Exhibit 46).
70
EXHIBIT 47
Population of Many Farms
1980-·2010
Population (thousands)
3.--------------
2.5 .--
2
1.5 L-----
1
0.5
--- ~ -,",..,.- ---" -.-
1980 1985 1990 2000 2005 2010
- 1980-1989 Projection ----- 1990-2010 Projection
Sources: 1980-1989 Pl'oJection. - NACOG;
1990-2010 ProJection. - [)epartment of
Economic Security, Fet,ruary 1990
Many Farms, north of Chinle, has grown by nearly 19% from 1980 to
1988 (see Exhibit 47). It is projected to increase by one-half
from 1988 to 2010, to over 2,400 people.
71
EXHIBIT 48
Population of Dilkon
1980-2010
Population (thousands)
1.6...---------------
----
1.2
-~ --
---"- ---
0.8
1985 1990 2010
f--'---l.--'--------'--!---'--.l.-....L---'----t----'---'---'-,.-l--t-I--,-1--'---'---.11--+1_1,--,---,--,-1--+1------,-1-1-.L-.....L..I_1
19195 2000 2005
Year
1980
0.4
-- 1980-1989 Projection ----- 1990-2010 Projection
Sources: 1980-11989 Projections - NACOG;
1990-2010 ProHections - Department of
Economic S,ocurlty. February 1990
Exhibits 48-49 include the two communities in proximity to S.R.
87. Dilkon is the smallest of the seven communities but has grown
at the fastest average annual rate from 1980 to 1988, exceeding 7%
(see Exhibit 48). Rapid growth in Dilkon is projected to continue
through the year 2010, to 1,450 people.
72
EXHIBIT 49
Population of Winslow
1980-·2010
Population (thousands)
14,..---------------
12
10
8
6
4
2
.. - .-
1980 1985 1990 1995
Year
2000 2005 2010
-- Estimate --_ .. Projection
Source: Estimates and Projectlons­Department
of Economic Security, 2/90
Winslow, at the southern terminus of S .R. 87 within the study
area, is the largest community of the seven (see Exhibit 49).
From a population estimated at 10,725 in 1988, the community is
projected to grow to over 12,300 by 2010. This is equivalent to a
1.3% average annual growth rate.
73
Overall, the population of t:he counties, reservations, and
communities in the corridor study area is projected to increase by
at least one-third during the 1988 to 2010 time period. Growth in
the Window Rock and Ft. Defiance area will exceed 70%. This
urbanization could significantly affect traffic levels on S.R. 264
near the New Mexico border through 2010.
since the 1970's, national employment has grown faster than
population, and ADT has grown faster still, leading to increased
mobility. This is due to social and economic changes such as job
growth, increasing participation in the labor force by women, and
increasing disposable incomes. The suburban lifestyle has become
more prevalent, further dispersing the origin and destination of
trips. These trends have resulted in more travel. According to the
U. S. Department of Transportation, total highway travel (vehicle
miles traveled) increased 56% between 1969 and 19833
• This is
three times the growth in overall population, which increased 16%.
With the "baby boom" generation peaking and with fewer people
reaching driving age, this national mobility trend may change.
While certain socio-economic trends in the corridor study area are
unique or even contrary to 'the nation, it is unlikely that any
differences would create a future scenario that greatly diverges
from national trends. Key socio-economic trends that will play a
role in determining future 'traffic trends both in the corridor
study area and Arizona are net migration, and disposable personal
income.
The following national and state projections were developed by the
WEFA Group, ADOT's Adminisitra'tive Services Division, and the
Arizona Department of Economic Security , respectively. For the
next ten years, national personal income is expected to have an
average annual growth rate of 6.8% (refer to Exhibit 50). Arizona
is expected to have a higher rate of personal income growth over
the same time period, averaging 8.4% annually. The national
population is forecast to increase about 0.9% a!lnually for the
next ten years (refer to Exhibit 51). Arizona's p6pulation growth
is expected to be more than twice the national average, at 2.6%
annually. Much of Arizona's population growth will be the result
of positive net migration. This will stimulate economic activity
and help increase Arizona's share of national income and employ­ment
for the next ten years. These trends are likely to be valid
in the corridor study area as well, although local potential and
policies for economic development will be key influencing factors.
3 U.S. Department of Transportation, Personal Travel in the
U.S., V. 1, Washington, D.C.: 1986.
74
EXHIBIT 50
Forecast Rates of Change
in Personal Incomte, AZ vs. US
0% ~-----''-------'-----'--------'--
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
Fiscal Y4~ar
2%
4%
6%
8%
Percent Change
10%r--------------
- Arizona : I U.S. I
Source.: Admlnl.tratlve Service. Dlvl.lon, The WEFA Group,
Arizona Department of Economic :Becurlty
75
E:XHIBIT 51
Forecast Hates of Change
in Population, AZ vs. US
Percent Change
2.::.-----------.:--........-~
2%
1.5%
1%+----+-----+--~
~-_.-+-.--~
0.5%
0% '--_---"__--'-__-'-__.-L-._---l.__~____L___'__ _____J
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
Fiscal Year
I AI:izona -+- u.s.
Soure••: Admlnl.tr.tlv. 8tlrvle•• Dlvl.lon, Th. WEFA Group,
Arlzon. D.partment 01 Eeol~omle 8eeurlty
shows the average annual rates of population growth for
states, Arizona, and the corridor study area from 1989
If past national trends continue, mobility should
a faster rate than population. This should hold true
and the corridor study area as well.
Exhibit 52
the United
to 1999.
increase at
for Arizona
EXHIBIT 52
Projected Average Annual Rates of Population Growth 1989-99
U.S. - Arizona - Corridor Counties
United States
Arizona
Apache, Coconino and Navajo Counties
0.9%
2.6%
2.2%
The projected average annual growth rate in ADT for S.R. 264 is
more than double the average annual growth rate of population for
the corridor study, but it is much lower for U.s. 191 and somewhat
lower for S.R. 87 (see Exhibit 53). However, S.R. 264 is pro­jected
to carryover twice the amount of traffic as the other two
routes combined by 1999, placing it as the dominant traffic
carrier of the area. Thus, it is expected that past trends in
mobility growth will continue for the next decade and are appli­cable
to the corridor study area.
76
EXHIBIT 53
Projected Average Annual Rates of ADT Growth 1989-99
U.S. 191 - S.R. 87 - S.R. 264
U.S. 191
S.R. 87
S.R. 264
1. 0%
2.0%
4.8%
The key factors of population and personal income has a direct
impact on travel and the amount of revenue available to operate
the road system. Highway revenues consist of collections from
fuel and vehicle license taxes and motor carriers, driver license
and title fees which are imposed on the users of Arizona's
highways.
The price structure for supporting t.he road system is based on two
principles: access to the system and frequency of use. Some costs
paid by users do not vary with the frequency of travel. Examples
of these costs include registration or driver license fees which
are access fees. Frequency of service and distance of travel
costs are paid by users in thE~ form of fuel taxes and motor
carrier fees. These costs vary with the amount of user travel.
However, regardless of how the user pays, what is being purchased
is use of the facility. Therefore, to estimate route revenue we
can observe our future travel demand. ADOT pUblishes traffic data
on the highway system once a year. 'rhis report provides counts of
traffic for commercial and non-commercial categories. Forecasts
of future travel demand are made but are not published on a
regular basis.
ADOT's, Administrative Services Division produces a ten-year
forecast of the Highway User RevEmuE~ Fund (H.U.R.F.). The fiscal
year 1989 H.U.R.F. forecast was analyzed to split J;evenues between
commercial and non-commercial. ~~here are nine revenue categories
that must be assigned into the two traffic categories. These
assignments are not perfect but they are reasonable. Results of
the revenue allocation exercise are shown in the Appendix L. By
relating the total generated to 1:he use of the road system we can
estimate the purchase price of travel access. For both traffic
categories, the relevant unit of measurement is vehicle miles of
travel.
The total 1988 statewide vehicle miles of travel (VMT) is
estimated at 30 billion. VMT is forecast to grow to 50.8 billion
for the year 2000. The total VMT for 1991 to 2000 ten year period
is 413.6 billion. The commercial class is assigned 18 billion of
the total VMT. The purchase price of commercial access is
estimated at 12.68 cents per mile Cif travel. The non-commercial
purchase price is 0.92 cents per mile of travel. Applying these
(constant 1990 $) unit prices to t.he corridors' forecast travel
results in an estimate of revenue generated on each corridor over
the 1991-2000 ten year period.
77
united states route 191 is estimated to generate $12,220,000 in
constant 1990 dollars during this ten year period. state Route 87
is anticipated to yield $3, :;.43,000 during the ten year period.
state Route 264 is the highest earner with $29,754,000 forecast to
be generated. The combined constant 1990 dollars total earnings
forecast for the three corridors is $45,519,000 (refer to Appendix
M). However, the total amount is not available to ADOT. Of the
total revenue collected in 'the H.U.R.F., ADOT's allocation is
about 50 percent of the total which is estimated at $22,760,000.
Capital for highway improvements comes primarily from the state's
share of the H. U. R. F. with federal aid a secondary source of
capital. Non-interstate roadways such as these corridors are
eligible for federal government capital participation. Through
the first quarter of 1989, federal aid participation rates were
over ninety-two percent for primary and secondary route improve­ments,
and eighty percent of the cost for rehabilitation and
replacement of bridges.
Federal money is guided by numerous stipulations regarding its
use. These stipulations can be used to categorize improvement by
program funding category. Over the fiscal year 1991-1992 program
period, federal aid is estimated to account for $79.6 million of
the total statewide federal aid available for these non-interstate
funding categories. For fiscal year 1992-1993 program period, the
federal aid is unknown and cannot be estimated. This infusion of
federal aid has had a inoculative impact upon the operation of the
state highway system.
Investment under a market system uses the information contained in
price in order to channel resources to meet the most urgent needs.
The infusion of external capital may obscure necessary knowledge
that price communicates which can lead to unproductive and to
unsustainable investment. The United states Department of Trans­portation
(U.S. DOT) has recognized the need to structure federal
assistance programs so that the assistance does not encourage
unnecessary or unwise investment~. To this end, U. S. DOT Secretary
Skinner has recently published a "Statement of National Transpor­tation
Policy". At this time it is not clear what impact the
federal transportation policies will have on Arizona. The u.s.
Congress plays the key role in authorizing structural changes and
providing funds to the u.s. DOT. Congress has not yet acted on
the legislative agenda.
78
ULTIMATE DEVELOPMENT CONCEPT
The ultimate development concept :in rural areas is normally a
single roadway prism with two through-traffic lanes, full
shoulders and with passing lanes in selected locations. In urban
areas the through-traffic lanes may be expanded to four lanes with
curb and gutter. This concept would allow numerous lengthy
reconstruction projects designed ultimately to fit the maximum
standards. This is in contrast to the level of development
concept which allows limited reconstruction projects of limited
length with less than maximum planning standards. Potential
improvements, illustrated in Exhibits 54 and 55 are based on
analysis of service, quality and facility condition of corridors
in concert with the ultimate development concept. However, the
inclusion of an issue or problem in this document does not
indicate that it is of sufficient: priority on a statewide basis to
receive a portion of the limited funding available.
EXHIBIT 54
POTENTIAL SHORT RANGE HIGHWAY IMPROVEMENTS
U.s. 191
OVERLAY OR RECONSTRUCTION
Approximate Location By Milepost
24.0 to 37.6 +
51.0 to 73.0 +4
74.0 to 103.0 +
105.0 to 106.0 +
109.0 to 126.0 +
Approximate Length In Miles
13.6 ±
22.0 ±
29.0 ±
1.0±
17.0 +
82.6 ±
STRUCTURE IMPFlOVEMENTS
Approximate Location By Milepost
69.29
96.02
jstructure
Cottonwood Wash Bridge
Chinle Wash Bridge
INTERSECTION IMPROVEMENTS
• Junction U.S. 191 (South) & S.R. 264
Junction U.S. 191 (North) & S.R. 264 & Indian Route 15*
• Junction U.S. 191 & Indian Route 7 (monitor traffic)
* Some improvements have recently been completed.
·WB M.P. 62 to 73 was overlain 1989
79
EXHIBIT 54 (Continued)
POTENTIAL SHORT &IlliGE HIGHWAY IMPROVEMENTS
S. R. 87
OVERLAY OR RECONSTRUCTION
Approximate Location By Milepost~ Approximate Length In Miles
353.0 to 354.0 ±* 1 +
358.0 to 369.0 +* 11 +
388.0 to 389.0 ± 1 +
392.0 to 406.0 + 14 +
27 +
* M.P. 346 to 358 was overlain in 1989
Long range improvements were not identified
S.R. 264
OVERLAY OR RECONSTRUCTION
Approximate Location By Milenos't Approximate Length In Miles
322 to 325± 3 ±
332 to 337± 5 +
340 to 348± 8 +
420 to 430± 10 +
434 to 435± 1 +
442 to 444± 2 +
472 to 476± ---±-...±
33 +
80
EXHIBIT 54 (Continued)
POTENTIAL SHORT RANGE HIGHWAY IMPROVEMENTS
STRUCTURE IMPROVEMENTS
S.R. 264
Approximate Location By Milepost
324.10
362.65
408.54
446.20
451. 30
!structure
Moenkopi Wash Bridge
Dinnebito Wash Bridge
Jeddito Wash Bridge
Ganado Wash Bridge
Fish Wash Bridge
INTERSECTION IMPROVEMENTS
Junction S.R. 264 & U.S. 160; Signals warrant study
Junction S.R. 264 & Indian Route 6
Junction S.R. 264 & Indian Route 12 (South); Monitor
traffic for signals warrant study
Junction S. R. 264 & Indian Route 12 (North); Signal
improvements
• Please refer to corridor u.S. 191 for recommendations on
junction S.R. 264 & U.S. 191
CLIMBING LANES
Approximate Milepost Or Location
458.0
469.0
* Per AASHTO Guidelines
81
~pproximate Length In Miles
1. 0*
1. 0 *
EXHIBIT 55
POTENTIAL LONG RANGE HIGHWAY IMPROVEMENTS
U.S. 191
OVERLAY OR R.ECONSTRUCTION
Approximate Location By Milepost,
15.5 to 23.0 +
Approximate Length In Miles
7.5 +
WIDEN
Approximate Location By Milepost~
11. 3 +
23.0 +
Approximate Length In Miles
4.2 +
1.0+
STRUCTURE IMPROVEMENTS
Approximate Location By Milepost
102.34
Structure
Agua Sal Bridge South
Approximate Location
By Milepost
0.5 +
18.0 +
23.0 +
37.6 +
43.6 +
72.0 +
87.7 +
104.3 +
73.0 +
96.0 +
OTHER IMPROVEMENTS
Approximate Length
In Miles
4,.0 +
2.0 +
2.0 +
1.0+
1.0+
4.0 +
4.0 ±
2.0 +
1.2+
18.0 +
82
Type of Work
Fencing
Fencing
Fencing
Fencing
Fencing
Fencing
Fencing
Fencing
Sidewalks, Street
Lighting, Access
Control
Management Plan,
Driveway
Management
Plan, Community
Awareness Program
Flatten Slopes
EXHIBIT 55(continued)
POTENTIAL LONG RANGE HIGHWAY IMPROVEMENTS
S.R. 264
OVERLAY OR RECONSTRUCTION
Approximate Location By Milepost
354 to 355 +
359 to 368 +
369 to 379 +
381 to 387 +
393 to 417.5 +
Approximate Length In Miles
1 +
9 ±
10 +
6 ±
24.5+
50.5±
STRUCTURE IMPROVEMENTS
Approximate Location By Milepost
387.30
387.94
400.00
418.55
419.30
;structure
8 - 3 X 57
3 - 10 X 8
3 - 12 X 10
5 - 4 X 60
3 - 5 X 71
78
39
WIlDEN
Begin Milepost or Location
458.0 +
469.0 +
Begin Milepost or Location
446.0 +
471. 6 +
:1\pproximate Length In Miles
1.0+
1.0+
WIDEN-UHBAN/RURAL
,1\pproximate Length In Miles
2.5 +
1.0+
CLIl'1BING LANES
Approximate Milepost or Location
370.0 +
381. 0
418.0
* Per AASHTO Guidelines
83
Approximate Length In Miles
1.6+
3.2 +
1. 0* Minimum
EXHIBIT 55 (continued)
POTENTIAL LONG RANGE HIGHWAY IMPROVEMENTS
S.R. 264
OTHER IMPROVEMENTS
Approximate Location
By Milepost
Approxi.mate Length
In Miles Type of Work
403.0 + 2:.0 + Fencing
426.0 ± 2.0 + Fencing
441. 0 + 6.0 + Fencing
455.0 ± 3.0 ± Fencing
472.0 + 1.0 + Fencing
322.0 ± 3.0 + Flatten Slopes
410.0 + ~~ . 0 + Flatten Slopes
471. 6 + 4.5 ± Sidewalks,
Street Lighting,
Access Control-
Management Plan,
Driveway Manage-ment
Plan,
Community Aware-ness
Program.
84
with the delineation of short and long range potential
improvements completed, the associated corridor investment
requirements can be estimated. This is in complement to the level
of development roadway improvements identified by the analytic
computer model. The ultimate development concept investment is
quantified in Exhibit 56. The ult,ima.te development concept roadway
investment requirements for all ·thr,ee corridors is $40,597,000 to
implement the short and long range findings. This cost was
calculated using 1988 price llevels and reflects the minimum
investment requirements. Excluded from the cost estimate are costs
for reconstruction of roadways and intersection improvements and
rights of way. The estimate includes costs for resurface; if
engineering evaluation of specific roadway proves reconstruction
is needed then, significant cost increases of $1.8 million per
mile minimum can be anticipated. For future analysis purposes, a
listing of factors by year used to estimate future price levels
can be found at Appendix K.
EXHIBIT 56
ULTIMATE DEVELOPM:ENT CONCEPT
SHORT AND LONG RANGE POTENTIAL CORlHDOR INVESTMENT REQUIREMENTS
($1,000 1988 Prices)*
IMPROVEMENT ~::ORRIDOR
~
U.S.191 S .!L-~37 S.R. 264 TOTALS
Roadway 15,956 3,942 20,699 40,597**
Structure 1,289 -()- 1,595 2,884
Pavement
Preservation 6,294 2,925 7,456 16,675
Routine
Maintenance 5,822 1,504 9,371 16,697
TOTAL 29,361 8,371 39,121 76,853
* Rounded.
** See Appendix 0 for comparison explanation.
Sources and Assumptions: Roadway-Cost based on Manual of Highway
Improvement and Maintenance Cost" .January, 1989. Excludes costs
for reconstruction of roadway, intersection improvements and
rights-of-way. Structure/Pavement Preservation/Routine
Maintenance-Costs based on 1990 Need Study (potential corridor
investment requirements-analytic :model), pavement preservation and
routine maintenance as identified in appendices I and J.
8:5
Finding sufficient financial rE~sources to implement potential
improvements presents a herculean effort to ADOT's managers. Are
the efforts of managers of ADOT in danger of being undermined by a
pUblic that continues to focus on desires and not what is
affordable, and in this process implement projects that increase
the states burdens with the ensuing economic consequences? It is
important to emphasize the 40.6 million dollar roadway-only
improvement investment is the~ minimum amount required under the
ultimate development concept. Given the lack of precision in the
cost manual and the un-quantified mileage for reconstruction
projects, this number is believed to be low. In addition, based
upon experience, this figurE~ i.s likely to be underestimated.
However, the amount is useful for financial analysis purposes if
it is clearly understood, actual costs are likely to be higher.
This raises a systemwide quest.ion: Should users of a facility pay
for benefits received?
86
APPENDIX A
LOCAL GOVERNMENT
GUIDELINES FOR DRIVEWAYS
It is desirable for the Chapte~r Houses and Tribal Council to
develop driveway and access guidlelines for all new development as
well as redevelopment of existing areas. The following is a
suggested draft set of driveway guidelines that could be applied.
These guidelines or a modified version should greatly reduce the
proliferation of driveway along sta'te highways and improve access
control. They should be incorporatled into existing Chapter House
Ordinances where not now included.
1. No driveway onto an arterial street or collector street
shall be located closler than 100 feet to the nearest
intersecting curb line.
2. One driveway will be permitted when the frontage is less
than 300 feet. Two drivev;rays will be permitted when the
frontage is 300 feet or greater.
3. Adjacent driveways should be no closer than 60 feet.
4. The use of shared drivevlays between adj acent parcels
should be encouraged whenlever possible.
5. Driveways on opposite sides of a street should not be
offset less than 150 feet.
6. A main driveway into a si.te should not -have any inter­sections
with parking aisles or on-site streets within
80 feet of the arterial street curb line.
7. No driveway within 100 fe:et of a median opening unless
it is directly opposite the opening.
The contents in this appendix do not necessarily reflect the
official policies of the STATE. This appendix does not constitute
a standard, specification, or regulation. In this regard, ADOT
has currently undertaken research on the issue of access
management and access management plans.
87
APPENDIX B
DRIVEWAYS AND ACCESS MANAGEMENT REFERENCES
Development of local ordinances and documents will be aided by
reviewing prominent reference pUblications. The following
publications should prove useful for transportation planning
standards.
Guidelines for Driveway Design and Location; ITE, 1974
Guidelines for Planning and Designing Access Systems for
Shopping Centers; ITE, 1975
• Guidelines for Control of Direct Access to Arterial
Highways; FHWA, 1975
Guidelines for Medial and Marginal Access Control on
Major Roadways; NCHRP, 1970
A Policy on Geometric Design of Highways and Streets;
AASHTO, 1984
• Guidelines for Urban l~ajor street Design; Institute of
Transportation Engineers (ITE) , 1984
Traffic Engineering Handbook; Institute of Transporta­tion
Engineers, 1984
• Manual on Uniform Traffic Control Devices; Federal
Highway Administration (FHWA), 1984
Transportation and Traffic Engineering Handbook, 2nd
Edition
Trip Generation Handbook, ITE, Current !dition
Transportation Research Board; Circular 212
Highway Capacity Mamu2lI, 1965; National Research Council
National Cooperative Highway Research Program, Report
186
•
•
•
•
National Cooperative Highway Research Program, Report
187
Highway capacity Manual, TRB Special Report 209
site Impact Traffic Evaluation, ITE
Traffic Impact Analysis, APA, PAS Report No. 387
state Highway Sy~tem Plan, ADOT, September, 1990,
Phoenix, AZ
88
APPENDIX C
Reported Accidemts on U.S. 191
1986 1987 1988 1989 Total ~
...2-
Segment 1 20 24 21 9 74 20.5
Segment 2 94 91 49 53 287 79.5
Totals 114 115 70 62 361 100.0
Injuries and Fatalities on U.S. 191
Injuries Fat:al;ities Total
Segment 1 54 5 59
Segment 2 148 9 157
Total 202 14
Accident By Type For U.S. 191
1986 1987 1988 1989 Total ~
...2-
Hit Animals 30 27 25 8 90 25.0
Ran-off
Roadway 31 9 15 17 72 20.0
Rear-end 9 16 9 5 39 11. 0
Overturned
In Road 2 20 8 2 32 9.0
Turning Left 8 3 3 9 23 6.0
Other 34 40 10 21 105 29.0
Total 114 115 70 62 361 100.0
89
Drivers' Physic§l Condition on U.S. 191
1986 1987 1988 1989 Total ~
.2-
No Apparent
Defects 113 107 65 63 348 70.7
Unknown 16 19 9 7 51 10.4
Alcohol
Related 20 30 15, 8 73 14.8
Sleepy/Fatigue
& Other 8 3 2: 7 20 4.0
Total 157 159 91 85 492* 100.0
* NOTE: Figures reported in the "total column differ from figures
reported for total acciden1:s. This is due to reporting
of physical condition for each driver in two vehicle
accidents.
90
APPENDIX D
Reported Accidents on S.R. 87
Segment 1 9 15 18 9
Total
51 100.0
Injuries and Fatalities on S.R. 87
Segment 1
Injuries
Fatalities
8
o
19
1
8
3
21
o
Total
56
4
100.0
100.0
Accident Types For S.R. 87
Ran-off
Roadway
Overturned
In Road
Hit Fixed
Object
Other
Total
7
o
1
1
9
3
4
2
6
15
2
7
2
7
18
3
1
1
4
9
Total
15
12
6
18
51
29.4
23.5
11. 8
35.3
100.0
Drivers' Physical Condition on S.R. ~7
No Apparent
Defects 1
Unknown 2
Alcohol
Related 2
Sleepy/Fatigue
& Other 4
7
4
5
2
12
7
3
1
4
5
3
1
Total
24
18
13
8
38.1
28.6
20.6
12.7
Total
* NOTE:
9 18 23 13 63* 100.0
Figures reported in the total column differ from figures
reported for total accidents. This is due to reporting
of physical condition of each driver in two vehicle
accidents.
91
APPENDIX E
Reported AccidE~nts on S.R. 264
1986 1987 1988 1989 Total ~
...2.
Segment 1 11 11 34 34 90 17.8
Segment 2 35 31 40 34 140 27.8
Segment 3 4 3 6 2 15 3.0
Segment 4 38 39 3 -ret.. 21 130 25.7
Segment 5 36 35 36 23 130 25.7
Total 124 119 148 114 505 100.0
Injuries and Fatalities on S.R. 264
1986 1987 1988 1989 Total ~
...2.
Segment 1
Injuries 6 13 3:2 36 80 23.1
Fatalities 1 1 :3 0 5 16.1
Segment 2
Injuries 16 22 27 26 91 26.2
Fatalities 5 1 .2 0 8 25.8
Segment 3
Injuries 2 7 4 0 13 3.7
Fatalities 0 0 0 0 0 0.0
Segment 4
Injuries 36 24 23 27 110 31.7
Fatalities 3 1 2 3 9 29.0
Segment 5
Injuries 9 15 15 7 46 13.3
Fatalities 1 1 6 1 9 29.0
Total
Injuries 69 81 101 96 347 100.0
Fatalities 10 4 13 4 31 100.0
92
Accident Types For S.R. 264
1986 1987 1988 1989 Total 9,-
...£.
Ran-off
Roadway 38 17 29 32 116 23.0
Hit Animals 24 21 25 16 86 17.0
Rear-end 15 13 21 18 67 13.3
Other 47 68 73 48 236 46.7
Total 124 119 148 114 505 100.0
Drivers' Physical Condition on S.R. 264
1986 1987 1988 1989 Total 9,-
...£.
No Apparent
Defects 114 119 151 120 504 69.6
Unknown 24 20 18 16 78 10.8
Alcohol
Related 27 26 31 24 108 14.9
sleepy/Fatigue
& Other 10 7 11 6 34 4.7
Total 175 172 211 166 724* 100.0
* NOTE: Figures reported in the total column differ from figures
reported for total accidents. This is due to reporting
of physical condition of each driver in two vehicle
accidents.
93
APPENDIX F
LEVEL OF DEVELOPMENT
Central to the ADOT assessment of System needs is the notion of
Level of Development, a planni.ng tool introduced as an integrative
concept in the recent StatE~ Highway System Plan. Level of
Development provides a hierarchical ordering of System routes into
five categories in terms of t:he relative importance of routes to
the System as a whole. The assignment to a Level of Development
category takes into consi.deration the route's functional
classification, level of significance, current and future daily
traffic, current and future truck traffic, and other unique route
characteristics (e.g., recreational use). The five levels of
development are described below.
Level of Development 1: IntE~rsitate and urban controlled-access
facilities form the backbone of the System. Among many functions
served, Level of Development 1 routes provide the principal means
of interstate travel, serve t,he greatest volume of traffic, link
the state's metropolitan areas, and provide the major truck
routes. These routes are built and maintained to the highest
standards.
Level of Development 2: In tE~rms of both use and function, Level
of Development 2 routes are the most important non-controlled
access routes statewide. For the most part, these routes were
constructed as two-l

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Full Text

TRT 5.2: R58U75
COPY 2
I n
f-.,..L), ! ..\
I ' , \
J \ ""1
A_riz;ona D~Eartrnent
Of Tra11sport.ahol1
ARIZONA DEPARTMENT OF TRANSPORTATION
J. Fife Symington
Governor
Charles E. Cowan
Director
Harry A. Reed
Transportation Planning Division
STATE TRANSPORTATION BOARD
Larry Chavez
Chainnan
Verne Seidel
Vice Chainnan
Members
Donald Denton
Hank Gietz
Sharon Megdal
Linda Brock Nelson
James Soto
22
u.s. 191, S.R. 87, S.R. 264
CORRIDOR STUDY
TABLE OF CONTENTS
Executive Summary
Page
Number
6
Foreword. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
Corridor Transportation Characteristics 24
Potential Corridor Needs 43
Corridor SUfficiency Ratings 47
Traffic Analysis of Corridor Routes 58
Ultimate Development Concept..•....•............. : ...•...... 79
Prepared by Arizona Department of Transportation,
Transportation Planning Division
Production Dates
8-9-91
1
EXHIBIT
NUMBER
1
2
3
4
5
6
7
8
9
10
11
12
13
LIST OF EXHIBITS
Page
Number
Five Year Construction 8
Short and Long Range Improvements 12
study Area Map.................................. .. 18
U.S. 191, Corridor Segment Map 21
S.R. 87, Corridor Segment Map 22
S.R. 264, Corridor Segment Map 23
l\T",......"'""~,.... ,...OF Lanes and Rights-of-Way, u.s. 191 ..•.... 25 .&.'\,,4J,LUJ~.L "" ...
Number of Lanes and Rights-of-Way, S.R. 87 ........ 25
Number of Lanes and Rights-of-Way, S.R. 264 ....... 25
All Routine Maintenance Activities-Cost Per Mile .. 27
Reported Accidents 1986-89 U.S.191, S.R.87,
S.R. 264 29
Injuries and Fatalities 1986-89 U.S.191,
S.R.87, S.R.264 .. 30
Accident by Type 1986-89 31
14 Drivers' Physical Condition 1986-89 33
15 Hierarchical Accident Comparisons on Segment 2 .... 33
16 Attributing Factors to Accidents on U.S. 191 34
17 Hierarchical Accident Comparisons on Segment 5 .... 39
18 Attributing Factors to Accidents on S.R. 264 40
19 Analytic Model Roadway Cross-section Potential
Improvements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 44
20
21
Analytic Model Structure Potential Improvements ... 45
Level of Development Concept, 1991-2000 Potential
Corridor Investment Requirements 46
2
22 1988 Pavement Life SUfficiency Map 51
23 Pavement Life Sufficiency Ratings 51
24 1988 Accident Rate SUfficiency Map 52
25 Accident Rate SUfficiency Ratings 52
26 1988 Accident Severity SUfficiency Map 53
27 Severity Rate Sufficiency Ratings 53
28 1988 Current Daily Traffic Per Lane
SUfficiency Map.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54
29 Current ADT SUfficiency Ratings 54
30 1988 Future Daily Traffic Per Lane
Sufficiency Map.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 55
31 Future ADT SUfficiency Ratings 55
32 1988 Deficiencies Map 56
33 Deficiency Factor Ratings 56
34 Composite SUfficiency Map 57
35 Composite SUfficiency Ratings 57
36 Actual and Projected ADT U.S. 191,
S.R. 87, S.R. 264 -i.e ••••••••• 58
37 Actual and Projected ADT U.S. 191, 1980-2010
by segment........................................ 59
38 Actual and Projected ADT S.R. 87, 1975-2010
by segment ,.,..;I;I;I;I.. 60
39 Actual and Projected ADT S.R. 264, 1975-2010
by segment........................................ 60
40 Population of Apache, Coconino and Navajo
Counties 1980-2010 64
41 Population of Navajo Nation 1980-2010 65
42 Population of Hopi Reservation 1980-2010 66
43 Population of Fort Defiance 1980-2010 67
44 Population of Window Rock 1980-2010 68
3
Population of
Population of
Population of
Population of
Population of
50 Forecast Rates of Change in Personal Income,
Arizona vs. united states 75
51 Forecast Rates of Change in Population,
Arizona vs. united States 76
52 Projected Average Annual Rates of Population
Growth 1989-1999, united states, Arizona,
Corridor Counties 76
53 Projected Average Annual Rates of ADT Growth
1989-1999 U.S. 191, S.R. 87, S.R. 264 77
54 Potential Short Range Highway Improvements 79
55 Potential Long Range Highway Improvements 82
56 Ultimate Development Concept, Short and Long
Range Potential Corridor Investment Requirements .. 85
4
Appendices
LIST OF APPENDICES
Page
Number
Appendix
Appendix
Appendix
Appendix
Appendix
A - Local Government Guidelines For Driveways ..... 87
B - Driveways and Access Management References .... 88
C - Accident Data U. S. 191 ........................ 89
D - Accident Data S .R. B7 ••••••••••••••••••••••••• 91
E - Accident Data S.R. 264 ........................ 92
Appendix F - Level of Development 94
Appendix G - Remedy Actions ...•............................ 96
Appendix H - Level of Development Concept, Analytic Model .. 98
Appendix I - Average Annual Pavement Preservation
Expenditures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 99
Appendix J - Routine Maintenance Cost Per Mile 100
Appendix K - Factors For Future Price Levels 101
Appendix L - H.U.R.F. Forecast Breakdown Into Commercial
And Non-Commercial 102
Appendix M - Estimated Corridor Revenue, Constant
1990 Dollars 103
Appendix N - Estimated Corridor Revenue, Current Dollars ... 104
Appendix 0 - Roadway Improvement Comparison 105
Appendix P - Five Year Construction Program 106
5
EXECUTIVE SUMMARY
Highways as a mode of transportation hold a significant market
share of goods and people both within and throughout Arizona. A
cost efficient and land use effective highway system is an
essential ingredient for the economy of Arizona. without an
adequate highway system, it is difficult to attract and maintain
economic activity.
ADOT has recognized the need to develop a comprehensive and
cooperative effort to insure that travel corridors are analyzed to
identify important components of the transportation network. In
fulfilling this important responsibility, ADOT has undertaken an
analysis of u.s. 191, S.R. 87, and S.R. 264 as travel corridors.
The statutory power to prioritize projects is placed with the
State Transportation Board, a seven me~her panel appointed by the
Governor. The Transportation Board is assisted in setting
priorities by a committee appointed by the ADOT Director known as
the Priority Planning Committee. Annually, ADOT publishes the
prioritized projects in a document title "Arizona's Five-Year
Transportation Facilities Construction Program". For your
convenience, improvement projects on u.s. 191, S.R. 87, S.R. 264
as reported in the construction program are presented on the
following page.
6
HIGHWAY IMPROVEMENTS AS IDENTIFIED
IN FIVE-YEAR CONSTRUCTION PROGRAM
(AS OF 5/91)
U.S. 191
Begin Milepost
11
23*
74
74
s. R. 87
Begin Milepost
361. 7
S.R. 264
Begin Milepost
359.6
367.0
373.9
402.9
446.0
446.0
470.0
474.0
475.0
N.A.
Approximate Length
in Miles
11. 9
14.6
0.4
13.8
Approximate Length
in Miles
6.3
Approximate Length
in Miles
13.3
0.3
10.1
23.1
0.6
2.0
2.6
2.0
0.1
N.A.
Type of Work
Double Chip Seal Coat
AC, Seal Coat & Guardrail
Lighting, SWlk, Turn Signals
SAMI, Overlay
Type of Work
AC, Seal Coat & Spot Level
Type of Work
Asphaltic Concrete (AC)
Intersect~on Improvement
AC, Seal Coat
AC, Seal Coat
Intersection Improvement
Landscape & Irrigation
Design Concept Study
Landscape & Irrigation
Signal Improvement, C&G & AC
Fence & Cattle Guard (Material
Only-Joint Project)
* Project underway
See Exhibit 1 for graphic illustration of improvements.
7
EXHIBIT 1
FIVE-YEAR CONSTR,UCTION PROGRAM
o
z
fTI
X
I~
Sanders
H E
Round Rock •
Teec· S
Nos Pos
• Rock Point
L Q -I CJ
,I
I,I,I
Dilkon •
N A V A J 0
Leupp
8
Many
Farms •
UTA H
Page
I ~ \~M08nkoPi i
Coal ,Mine Mesa
- . ~
-_ ®
.SHORT RANGE IMPROVEMENTS
lONG RANGE' IMPROVEMENTS
12
The following identified improvements are based on analysis of
service quality and facility condition of corridors in concert
with the level of development concept.
POTENTIAL HIGHWAY IMPROVEMENTS
LEVEL OF DEVELOPMENT CONCEPT
CORRIDOR U.S. 191
SHORT RANGE
o Reconstruction of approximately one-quarter mile of roadway.
o Overlay approximately eighty-six (86) miles of roadway.
o Make structure improvements to Cottonwood and Chinle bridges.
LONG RANGE
o Overlay approximately fourteen (14) miles of roadway.
o Make structure improvements to Agua Sal bridge.
CORRIDOR S.R. 87
SHORT RANGE
o Overlay approximately forty-five (45) miles of roadway.
CORRIDOR S.R. 264
SHORT RANGE
o Make structure improvements to Moenkopi, Dinnebito, Jeddito,
Ganado and Fish bridges.
LONG RANGE
o Overlay approximately one mile of roadway.
o Make structure improvements at five locations.
13
POTENTIAL TRAFFIC AND INVESTMENT REQUIREMENTS
Financial resources provide a vital element for meeting transportation
requirements. To address these requirements, ADOT has relied on
transportation user fees. Obtaining sufficient financial resources to
implement potential improvements is a continuous statewide challenge.
Estimated costs under both the ultimate and level of development concepts
are minimum amounts required. Actual costs are likely to be higher. This
system-wide financial challenge requires judicious evaluation of actual
construction projects. Criteria traditionally applied includes the belief
that transportation users bear an appropriate share of the costs of
facilities they use and that those who are paying user charges will benefit
from them.
The following chart, which summarizes future traffic and investment
requirements, provides useful information for financial analysis purposes.
FUTURE TRAFFIC AND POTENTIAL
CORRIDOR INVESTMENT REQUIREMENTS
($1,000 1988 Prices)*
COFRIDOR
FUTURE TRAFFIC A
Average Daily
Traffic
u.s. 191
1,800
s. R. 87
1,200
S.R. 264
7,500
TOTALS
N/A
702
Million Vehicle
Miles Traveled (V.M.T) 204 2,094 N/A
VARIABLE COSTS
Ultimate Development
Concept (D.D.C.)
Level of Development
Concept (L.D.C.)
FIXED COSTS
Pavement
Preservation
Routine
Maintenance
COST TOTALS
U.D.C./
Cost Per V.M.T.
L.D.C./
Cost Per V.M.T.
$17,245
$14,526
$ 6,294
$ 5,822
$29,361/
4.1¢
$26,642/
3.8¢
$3,942
$3,408
$2,925
$1,504
$8,371/
4.1¢
$7,837
3.8¢
$22,294
$ 1,631
$ 7,456
$ 9,371
$39,121/
1. 8¢
$18,458
0.9¢
$43,481
$19,565
$16,675
$16,697
$76,853
$52,937
*Rounded
A=1991-2000 Time Period
14
LAND/USE MANAGEMENT OF HIGHWAY ACCESS
1. Enhance coordination efforts between ADOT, federal agencies,
tribal and local governments in providing adequate setbacks and
ingress/egress control. Diligent attention will be required from
the Bureau of Indian Affairs, Housing and Urban Development, and
ADOT to ensure that proper development and highway compatibilities
are provided for in future development.
2. Future residential commercial and recreational developments
should be encouraged to develop in planned cluster districts or
other such designs which enhance the function of state highways
and avoid the proliferation of access points to the highway.
3. ADOT in conjunction with the Bureau of Indian Affairs,
Housing and Urban Development, and tribal Governments should
develop enhanced administrative procedures to obtain needed
rights-of-way, borrow and storage sites for proposed highway
improvements. Obtain from B. I .A. financial assistance to the
state when local growth, development opportunities demand roadway
improvements. Require developers and land owners to dedicate
needed rights-of-way and provide financial assistance to the state
in conjunction with governing authorities when development
opportunities demand roadway improvements.
4. Due to the unique sovereign status of Indian land, ADOT,
tribal governments and B.I.A. should develop policies, procedures,
regulations and statues that reduce conflicts which hamper normal
operational aspects of state routes. Enhancement of the
operational environment could result in reduced transportation
costs and better service.
5. ADOT's Transportation Planning Division should take the lead
role with research and development of rules concerning access
management on State roadways as a possible lower cost alternative
to the traditional methods of improving travel time and safety.
TRANSPORTATION SAFETY
1. A.DOT in conjunction with tribal governments, the Bureau of
Indian Affairs, and the Department of Health and Human Services
should implement methods to improve training for accident
investigators and to improve administrative procedures for the
filing of accident reports with DOT. The lack of precision in
data collection and reporting may create difficulty in detecting
potential hazards and advances cost inefficient transportation.
2. Alcohol is a significant contributing factor to accidents on
state highways. ADOT, in conjunction with tribal governments, the
Bureau of Indian Affairs and the Department of Health and Human
Services, should consider implementation of community awareness
15
programs intended to inform the pUblic about the dangers of
drinking and driving to reduce the alcohol-related accidents.
Another option is stepped-up patrol of highways.
3. Numerous accidents also result from vehicles striking animals
on the highway. ADOT in conjunction with tribal governments, the
Bureau of Indian Affairs, and the Department of Health and Human
Services should consider implementation of community awareness
programs intended to reduce the high rate of animal incidents.
Enhanced enforcement of animal control should also be
investigated.
4. In some urbanizing areas, properties abutting the highway have
numerous driveways and streets which are frequently offset. Highly
unregulated access coupled with offset streets promotes traffic
conflict on the highway. ADOT in conjunction with tribal
governments, and the Bureau of Indian Affairs should investigate
methods and locations which reduce traffic conflict caused by
unregulated access and offset street intersections. -
16
FOREWORD
The transportation systems in Arizona have had a significant
impact on the growth of the economy, the utilization of land, and
the life styles enjoyed by citizens throughout the state.
Transportation facilities serve all regions of the state; they are
connecting links as well as arterials over which flow the goods
and services essential to every day living. u.s. 191, S.R. 87,
and S.R. 264 are three of these connecting links located in
Northeastern Arizona. (See Exhibit 3).
ADOT has recognized the need to develop a comprehensive and
cooperative effort to insure that these travel corridors are
analyzed and remain important components of the transportation
network. In fulfilling this important responsibility, ADOT has
undertaken an analysis of these three corridors. The analysis
reviews existing characteristics and identifies the short term and
the long range potential needs (6 + years) for transportation
improvements within the three travel corridors. Where applicable,
recommendations for short and long term improvements to meet these
needs are listed.
It should be emphasized that the purpose of this study is not to
identify detailed engineering solutions, but to highlight existing
and future capacity and/or operational problems. An environmental
inventory/assessment is beyond the scope of this report. This
data collection process did not involve review of documents, plans
and studies relevant to: threatened and endangered species;
archaeological, historical, or architecturally significant
properties; parks or recreational facilities, prime agricultural
lands; noise sensitive receptors; air quality; geologic hazards;
mineral resources or floodplains. However this study does tend to
focus on desires and what is affordable.
Further study efforts are necessary to develop engineering reports
and implementation plans. Proposed highway improvements identi­fied
through technical studies such as a Corridor Study typically
far exceed the available revenue over a five year construction
program. The inclusion of a problem or identification of a
proposed improvement in this document does not indicate that it is
of sufficient priority on a statewide basis to receive a portion
of the limited funding available. However, it does lead to the
next and most difficult phase of the programming process:
prioritizing highway improvements. The statutory power to
prioritize projects is placed with the State Transportation Board,
a seven member panel appointed by the Governor.
17
EXHIBIT 3
STUDY AREA
Study
Area.
U T A H
Teec • 8
Nos Pos
8 ,I,I
z
, 1"1
i I, 1:£
II
3::
N A V A J oj E
1"1 ,I
x
,I
()
0
o 25
MILES
18
50
INTRODUCTION
UNITED STATES ROUTE 191
This corridor, located entirely in Apache County, begins at the
junction with Interstate 40 near Chambers, and extends northerly
to the junction of State Route 264 at the Navajo settlement of
Ganado. At this location, united States Route 191 overlaps state
Route 264 and continues west for approximately six miles until the
junction of Indian Route 15, state Route 264 and United states
Route 191 (U.S. 191). At this junction, U.s. 191 extends norther­ly
through the Navajo settlement of Chinle, Many Farms and Round
Rock to the junction with U.s. Route 160 near the settlement of
Mexican Water. The corridor does not include the portion of U.s.
191 from u.s. 160 to the Utah State Line. This portion is
administered by the Bureau of Indian Affairs.
To facilitate analysis of data, this corridor has been divided
into two segments. The first segment is between Chambers and
Ganado for a distance of 37.63 miles. The topography in this area
consists of rolling and flat plateau desert with elevations in the
6,000 foot range. Segment two is 92.49 miles in length between
Ganado and Mexican Water. This segment's topography also consists
of flat and rolling desert with elevations of 6,000 feet at the
southern end to 5,000 feet on the northern portion. The total
corridor length is 130.12 miles. A segment map of the U.s. 191
corridor is shown in Exhibit 4.
STATE ROUTE 87
This corridor, located entirely in Navajo County, begins at the
junction with Interstate 40 near Winslow, and extends northerly to
the junction of State Route 264 at the Hopi settlement of Second
Mesa. Approximately 16 miles of this corridor is located off the
reservation and about 44 miles are on the Navajo Nation and Hopi
ReserVation. Corridor topography consists of flat desert with
elevations ranging from about 4,800 feet near Winslow to over
6,000 feet at the junction of State Route 264. A segment map of
the S.R. 87 corridor is shown in Exhibit 5. The total corridor
length is 60.47 miles.
19
STATE ROUTE 264
This corridor begins at the junction of united States Route 160
near Tuba city and extends easterly through Coconino, Navajo and
Apache Counties to the Arizona - New Mexico State Line. This
route begins and ends in the Navajo Nation yet passes through the
Hopi Reservation.
This corridor has been divided into five segments to facilitate
analysis of data. The first segment is between the Navajo settle­ment
of Tuba City (milepost 321.97) and the Hopi settlement of
Second Mesa (milepost 384.21) for a total distance of 62.24 miles.
The topography for segment one consists of rolling and flat
plateau desert with elevations around 4,600 feet. Segment two
starts at milepost 384.21 which is also the junction with S. R. 87
and ends at the junction of U.S. 191 or milepost 446.89 near
Ganado, a distance of 62.68 miles. The topography of segment two
is typically flat to rolling desert with elevations ranging from
4,000 to over 6,000 feet. Segment three consist of a two-mile
length of highway through the Navajo settlement of Ganado. Segment
four starts at milepost 448.89 and ends at milepost 471.62 near
St. Michaels, a distance of 22.73 miles. Near Ganado, the roadway
elevation climbs from 6,300 feet to over 7,700 feet at the Summit
and than descends to about 6,800 feet in the st. Michaels area.
Segment five, the last segment, is a 4.50 mile length of highway
connecting st. Michaels, Window Rock and the state line at
milepost 476.12. Segments for S.R. 264 are shown in Exhibit 6.
20
US 191 SEGMENTS
UTA H
EXHIBIT 4
8
Ncameron
Teec • 8
Nos Pas
Z
fT1
:E
E
;::
fT1
X
(")
1° Cross
Canyon Window
Rock
•
CD
0 25 50
MILES
SEGMENT NO. MILEPOST LOCATION LENGTH
CD 0.00 37.63 37.63
® 43.85 136.34 92.49
TOTAL MILES 130.12
21
EXHIBIT 5
Teec
Nos Pos
z
Round Rock • ",
~
A C H E 3':
",
• Chinle X
(") /0
Cross
Canyon Window
Rock•
A P
8
SR 87 SEGMENTS
UTA H
,I
II,
! Many I Farms·
I
NAVAJO/
,
8 • Moenkopi i I Coal ,Mine Mesa ' ~ 1 ~-'-"'l !) I '-( Cameron 8 i_Q pOla;.:.a~~:~~~1 ~,,' ~
: uralDI - . ;:'leamooat
I , • i L_ j
,I
I Leupp ,
· 8 !
I
o 25 50
MILES
SEGMENT NO. MILEPOST LOCATION LENGTH
CD 345.57 - 406.04 60.47
22
EXHIBIT 6
SR 264 SEGMENTS
z
r1
X
Round Rock •
A PAC H E
• Chinle
Many
Farms •
UTA H
Tuba City N A V A J
•
Sanders
8
8
0 25 50
MILES
SEGMENT NO. MILEPOST LOCATION LENGTH
CD 321.97 384.21 62.24
® 384.21 446.89 62.68
® 446.89 448.89 2.00
@) 448.89 471.62 22.73
® 471.62 476.12 4.50
TOTAL MILES 154.15
23
CORRIDOR TRANSPORTATION CHARACTERISTICS
In the following pages, historical characteristics are identified
in terms of existing rights-of-way, surface maintenance costs, and
accident statistics. Corridor analyses include these characteris­tics
as they can help highlight problem areas that may need
corrective action. Pavement deterioration, including cracks and
crumbling edges, are indications of sub-grade or surface failure
which will lead to high maintenance costs.
Some of the sources consulted for this corridor study include the
current Five Year Highway Construction Program, (1990-94)
accident records, the State Highway System Log, the State Traffic
Log, sufficiency ratings, bridge records and population data.
RIGHT-OF-WAY
In most cases, right~of-way in these corridors appears to be
adequate to provide for future projects. There is at least 200
feet of right-of-way on each route with the exception as noted
below and in the exhibits. u.S. 191 segment 2 has some mileage
with right-of-way limited to 80 feet. On S.R. 264, segment 1 has
limitations of 100 feet through Moencopi; segment 4 has some
mileage with 150 feet and segment 5 has a significant amount of
right-of-way limited to 100 feet.
If any of these segments were to be reconstructed or widened, then
additional right-of-way might be necessary. Exhibit 7 shows the
number of lines and rights-of-way for u.S. 191, Exhibit 8 shows
S.R. 87, and S.R. 264 is shown in Exhibit 9.
Specific right-of-way requirements for major improvement projects
are precisely known once the engineering plans have been devel­oped.
For proposed projects to rapidly proceed to construction,
it is vital to mitigate right-of-way and access disputes. Time
delays and their associated expense are frequently encountered
when DOT finds it necessary to acquire right-of-way as part of an
improvement project. This is especially critical when projects
are located within the Navaj o-Hopi j oint use disputed areas.
These difficulties increase the risk of allocated financial
resources being reallocated to projects that can be implemented in
an expeditious manner.
Due to layering and overlapping roles of governments (i.e. Bureau
of Indian Affairs, Tribal Council and Chapter House, State and
County Government) it can be difficult to determine "rights" and
"authority" concerning matters of highway right-of-way and access.
A reduction in the layering of government would relieve the time
spent processing projects on the Indian reservations. It is not
anticipated that this issue will be resolved in a timely manner.
24
LOCATION
EXHIBIT 7
NUMBER OF LANES AND RIGHTS-OF-WAY
U. S. 191
NUMBER OF LANES
R.O.W.
AVAILABLE
SEGMENT 1
MP 0.00-37.63
SEGMENT 2
MP 43.85-136.34
(MP 73.22-74.31)
2 Travel Lanes
2 Travel Lanes
(4 Travel Lanes)
200 feet
80-250 feet
LOCATION
SEGMENT 1
MP 345.57-406.04
EXHIBIT 8
NUMBER OF LANES AND RIGHTS-OF-WAY
S = R= 87
NUMBER OF LANES
2 Travel Lanes
D n TAl
.I"\.. V • r., •
AVAILABLE
200 feet
LOCATION
SEGMENT 1
MP 321.97-384.21
EXHIBIT 9
NUMBER OF LANES AND RIGHTS-OF-WAY
S. R. 264
NUMBER OF LANES
2 Travel Lanes
R.O.W.
AVAILABLE
100-200 feet
SEGMENT 2
MP 384.21-446.89
(MP 403.02-403.41)
SEGMENT 3
MP 446.89-448.89
SEGMENT 4
MP 448.89-471.62
SEGMENT 5
MP 471.62-472.63
(MP 472.63-476.12)
2 Travel Lanes
(4 Travel Lanes)
2 Travel Lanes
2 Travel Lanes
2 Travel Lanes
(4 Travel Lanes)
25
150-200 feet
200 feet
150-200 feet
100-200 feet
PAVEMENT SURFACE MAINTENANCE
ADOT's goal in maintenance activities is the preservation and
restoration of the State's roadways and related facilities. These
activities are broken down into specific work responsibilities and
into segments, based on variations in traffic volume, user
characteristics, and adjacent land uses.
Previous corridor studies used routine pavement surface
maintenance costs as a major method to locate pavement
deficiencies. The surface maintenance costs over a three year
period were used to identify deficiencies. These deficiencies were
generally a symptom of problems associated with unstable soils or
drainage of base materials which, given time, resulted in
deficient surface pavement. This condition would prompt
maintenance expenditures on surface pavement.
This analytical method was devised to estimate costs of routine
maintenance which consists of patching, sealing and seal coating
the roadway surface. Application of this statistic indicates
specific sections of roadway that require frequent or extensive
surface maintenance or extensive reconstruction of roadway base.
This study's analysis and application of routine maintenance costs
has departed from the previous method used to calculate routine
maintenance costs. In addition to surface maintenance costs, the
sUfficiency rating system is also used as an indicator of roadway
sections in need of reconstruction or overlay.
This report considers all maintenance costs including traffic
control, overhead activities, and snow and ice removal. This
change now reflects the costs of maintaining stat~ highways.
In order to provide a relative measure of maintenance costs, the
following table was developed for use in other corridor studies.
ALL ROUTINE MAINTENANCE
Low
Medium
High
ACTIVITIES-COST PER
$ 0 to
$2,800 to
$5,700 or
MILE OF
$2,799
$5,699
Greater
ROADWAY
Corridor maintenance cost have been calculated for 1986 (07/86­12/
86), 1987, 1988, and 1989 (01/89-07/89). Costs for all
corridor segments are shown in Exhibit 10. Of the approximately
345 miles of highway under study, about 80 percent of this mileage
is in the low to medium maintenance cost range. However, of the
five corridor segments for S.R. 264, the remaining 20 percent of
high cost mileage is found in three corridor segments. Two of
these high maintenance cost segments encompass areas primarily
near small urban areas--those near Second Mesa and Window Rock.
Those segments have an average maintenance cost of $6,421 and
$8,074 per mile, respectively.
26
EXHIBIT 10
ALL ROUTINE MAINTENANCE ACTIVITIES-COST PER MILE
u. S. 191
SEGMENT
1989 (1/2 yr. ) AVERAGE
SEGMENT
NUMBER
1
2
1
1
2
3
4
5
1986 (1/2 yr.)
$2058
3800
$973
$1685
3119
2214
1304
1951
$4179
3957
S. R. 87
$1884
S. R. 264
$5783
5676
5902
4109
9749
27
$6080
2540
$4107
$4933
4044
6189
5537
6522
$1542
2685
$497
$4285
4894
4958
2325
6001
$4620
4327
$2487
$5562
5911
6421
4425
8074
CORRIDOR ROADWAY ACCIDENT DATA
ADOT's Traffic Records Unit compiles data on a statewide basis
from accident reports which are submitted by state and local
governments as well as reservation agencies. This database was
accessed and historical accident data over a four-year period from
1986 to 1989 is presented in this section as a general review of
accidents. ADOT's Traffic Records unit produces standardized
reports which contain data on the type of accident, time, date and
location of accident.
The traditional debate on the causes of traffic accidents has been
whether the highway, the vehicle, or the driver "caused" a given
accident. In the overwhelming majority of traffic accidents, the
single cause (factor) approach represents a gross over-simplifica­tion.
A more complex system of multiple variable exists in the
environment of traffic accidents. Identification of those
combinations of factors responsible for accidents requires
comparing accidents for consistent factor combinations with and
without the safety related features being studied. This identifi­cation
of factor combinations is beyond the purpose of this
corridor report.
An objective of this report is to identify potential problems and
place them into perspective so that effective countermeasures can
be developed and evaluated for subsequent implementation. Conclu­sions
derived from accident, travel and geometric data are
essential to identify study areas, identify promising countermea­sures,
and to evaluate the effectiveness of countermeasures.
However, accident data alone cannot provide a definitive answer.
Prevention of accidents relies on a systematic ~ approach which
addresses several factors. continued improvements to safety
depend upon acceptance and application of proven techniques which
address the broad spectrum - the highway, the vehicle, and the
driver. Roadway accident data presented in this section is an
alternative and complimentary method to the Sufficiency Rating
System for reviewing corridor safety. The review of accident data
presented in the report is just a small part of a systematic
approach.
u.s. 191
Over the four-year study period, a total of 361 accidents were
reported on U.S. 191. Exhibit 11 shows the frequency distribution
of these accidents by segment. The majority of accidents occurred
on segment 2. These accidents yielded 202 injuries and 14
fatalities as shown in Exhibit 12.
28
EXHIBIT 11
REPORTED ACCIDENTS 1986-1989*
Route
u.s. 191
Segment 1
Segment 2
Total
s. R. 87
Segment 1
S.R. 264
Segment 1
Segment 2
Segment 3
Segment 4
Segment 5
Total
Milage
37.63
92.49
130.12
60.47
62.24
62.68
2.00
22.73
4.50
154.15
Total Accidents
74
287
361
51
90
140
15
130
130
505
Percentage
20.5
79.5
100.0
100.0
17.8
27.8
3.0
25.7
25.7
100.0
* Note: Unless otherwise noted the accident data presented in
this study includes all types of reported accidents, and
data on accident locations was reviewed and is presented
in an aggregate manner unless otherwise noted. The
comparisons between accident type percentages on given
highway sections to statewide accident type percentages
may not be valid statistical comparisons.
29
EXHIBIT 12
INJURIES AND FATALITIES 1986-1989
vovn - 23~1% 5 - 16.1% 85
91 - _, _D_ o ''It:: 09.- 00 ~o.,""4Ilii11~ ~~~~ ~4U'-'~.IA~ ~. ~ .. ~.., ~. ";"'\oo;oV"~"'':'1
(4) adopt a circulation plan i plan for future growth
and street system/evaluate site plans for accor­dance
with long range plan; and
(5) provide for highway appurtenances to help direct traffic
(raised medians, curbing and sidewalks).
Additional information regarding the development of access
guidelines can be found in Appendix A and B.
The number of accidents outside the initial CLOSE study area may
suggest that additional inspection of highway might be warranted
in the future. If so, it may justify additional traffic engineer­ing
studies to determine if corrective steps are needed. Poten­tial
concepts to explore are:
• Community Awareness Programs
• Access Control/Driveway Guidelines
• Speed zone reductions
• Sign and pavement markings
• Curb, sidewalks, street lights
Animal control enforcement
• R-O-W fence modification
It is recognized that many accidents are caused by operator error
and in some cases substance abuse. Design-related changes to the
35
roadway will probably not prevent these type of accidents from
reoccurring, however community awareness programs intended to
inform the public about the dangers of drinking and driving may
assist in efforts to prevent alcohol-related accidents.
S. R. 87
During the four-year study period from 1986 to 1989, a total of 51
accidents occurred on the 60.47-mile stretch of S.R. 87~ Accord­ing
to reports issued by Traffic Studies, these accidents caused
56 injuries and 4 fatalities. Please refer to Exhibits 11 and 12.
The most frequent type of accident on this segment of highway were
vehicles running off the road with 15 occurrences or 29 percent.
Exhibit 13 provides a breakdown of the type of accidents. Twenty­four
percent or 12 accidents involved vehicles overturned in the
roadway. Data for drivers' physical condition are found in
Exhibit 14. Alcohol was a factor in 21 percent of the accidents
and fatigue was a factor in 13 percent of the accidents.
S.R. 264
This route is the longest highway under consideration in this
corridor study. Along its 154.15-mile roadway, 505 accidents
were reported during the four-year period. The breakdown of
accidents by segment is shown in Exhibit 11.
Although final figures from Traffic Studies are revised as new
accident records from the reservations are received, recent data
shown in Exhibit 12 indicate that these accidents produced 347
injuries and 31 fatalities over the span of 4 years.
The type of accidents occurring most frequently on S.R. 264
involve vehicles running off the road, 23 percent; hit animals, 17
percent; and rear-end collisions, 13 percent. The type of
accidents occurring most frequently are shown in Exhibit 13.
Fifteen percent of the accidents were influenced by alcohol.
Exhibit 14 also shows that fatigue was a contributing factor in 7
percent of the accidents.
S.R. 264 seqment 1
The 62.24 mile segment comprises 40 percent of the entire route
mileage, only 18 percent of the accidents occurred here. The most
frequent accident type--43 percent of all accidents on this
segment--involved vehicles running off of the roadway. This is
higher than the average of 23 percent for the highway. Vehicle
collision types involving rear-end, striking fixed objects, and
overturning on the roadway contributed another 37 percent to the
overall number of accidents.
36
S.R. 264 Seqment 2
The largest of the segments, this 62.68 mile stretch is 41 percent
of the total route mileage and accounted for 28 percent of all
accidents. Vehicles running off of the roadway or striking
livestock were the cause of 74 accidents--over half of the
accidents on this stretch of highway. This coincides with the
high percentage--71 percent--of accidents (99) that are single
vehicle.
S.R. 264 Seqment 3
This two mile segment is the smallest of the five segments.
Fifteen accidents occurred on this segment of highway resulting in
13 injuries. According to accident reports, no fatalities
occurred on this segment. The small number of accidents prevents
any meaningful hypothesis to be drawn.
S.R. 264 Seqment 4
This 22.73-mile segment of roadway produced nearly one-third of
all injuries occurring on SoRe 264 during the 4-year period; it
also tied segment 5 for the total number of highway fatalities--9.
This segment comprises just 15 percent of the corridor highway
mileage and has a relatively higher average daily traffic volume.
Fifty-three percent of all reported accidents have been from
vehicles leaving the roadway or striking livestock. By contrast,
the SoRe 264 corridor average for these combined accidents is 40
percent. Eleven percent of the accidents were rear-end
collisions.
S.R. 264 seqment 5
Two-car collisions are more prominent on this 4.5 mile segment of
roadway near Window Rock where 2 out of 3 accidents involve two
vehicles. This is consistent with the relatively more urbanized
environment of Window Rock compared with other areas on the
corridor. The most frequent accident types are rear-end and angle
collisions. Each comprised 18 percent of the total number of
accidents 0 This too, is an indication of an urban environment
characterized by higher volumes of traffic and numerous access
points abutting the roadway. Surprisingly, animals struck on the
roadway account for 12 percent of the accidents.
37
Review of the 1988 Accident Rate SUfficiency system categorized
the area between mileposts 473.00 and 474.00 as being poor. This
rating in an urbanized area prompted a review of accident records
from 1986 through 1989 for segment 5. Over the 4-year study
period, 130 accidents resulting in 46 injuries and 9 fatalities
occurred on this 4.5 mile segment. These findings promoted
additional analysis of this segment. An analysis of accidents
occurring between mileposts 472.63 and 476.12 was selected due to
its status as a 4-lane roadway. Exhibit 17 illustrates the number
of accidents, injuries, and fatalities on both segment 5 (4.5
miles) and the 3.49 mile study section of 4-lane roadway. The
study section has approximately 94 percent of all accidents, about
96 percent of all injuries and 100 percent of the fatalities for
segment 5. In addition, the study section comprises 24 percent of
the accidents and 29 percent of the fatalities for the entire
corridor S.R. 264.
38
EXHIBIT 17
Hierarchical Accident Comparisons on Segment 5
1986 1987 1988 1989 Total ~
2-
Segment 5
M.P. 471.62 - 476.12
Accidents 36 35 36 23 130 100.0
Injuries 9 15 15 7 46 100.0
Fatalities 1 1 6 1 9 100.0
segment 5
M.P. 472.63 -
476.12
Accidents 32 33 34 23 122 93.8
Injuries 8 14 15 7 44 95.6
Fatalities 1 1 6 1 9 100.0
The CLOSE report compiled by the Traffic Studies Branch in May,
1990 focused on S.R. 264 between mileposts 473.66 and 473.77. The
CLOSE report found that many accidents recorded at milepost
473.66, the intersection of S.R. 264 and Indian Route 12 (south),
was in error; those accidents actually occurred at milepost
475.49, the intersection of S.R. 264 and Indian Route 12 (north).
Therefore the focus of the CLOSE findings deals with the north
intersection at milepost 475.49. The report cites that 30
accidents and 7 injuries were recorded between 1985 and 1988.
There were no fatalities. The CLOSE report recommended hardware
improvements to the signals including left turn phasing.
Exhibit 18 indicates there are several consistent contributing
factors to accidents in Window Rock. The two largest contributors
to accidents in this section involved intersections and driveways
accounting for 62 of the 134 total factor combinations. Intersec­tion-
related collisions were the largest contributing factor
involving 36 accidents and 26 driveway-related accidents. Most of
these--74 percent-were 2- and 3-car accidents. The majority of
these accidents were property damage only and did not involve
serious injuries or fatalities.
There is concern for the large number of accidents that cause
minor injuries and the economic costs associated with them. This
combined number of accidents involving intersections and driveways
is linked to the number of turnouts on and off of the highway.
The large percentage of mUltiple-car collisions also signifies the
extent of the contiguous built-up area in Window Rock and the need
to adjust to the more urbanized conditions.
39
EXHIBIT 18
ATTRIBUTING FACTORS TO ACCIDENTS ON S.R. 264
M.P. 472.63 - 476.12
Total
Total
Accidents" 32 33 34 23 . 122
Driveway
Access 12 4 7 3 26
Intersection 7 10 12 7 36
Alcohol 5 6 5 4 20
Pedestrian/
Pedalcyclists 1 2 4, ,... 8
Animals 3 5 2 2 12
Other"" 7 8 8 9 32
.. .... More than one factor may cause an accident. All other factors not identified in exhibit.
Records indicate that there were 8 pedestrian/pedalcyclist
accidents involving four fatalities.
Properties accessing the highway could contribute to the number of
accidents relating to driveway access. The area abutting the
highway has numerous driveways and streets which are frequently
offset. Unregulated access coupled with a large number of offset
streets abutting the highway right-of-way promotes traffic
conflict. A prescription for managing access on state highways is
currently being developed, however some steps could be taken by
the Chapter House and Tribal Council in the interim to help
mitigate the situation.
40
Proposed steps might include the following:
(1) eliminate unnecessary driveways;
(2) provide incentives to construct shared or common drive­ways;
(3) develop driveway guidelines-the spacing and realignment
of offset streets and driveways are needed to decrease
the amount of side friction;
(4) adopt a circulation plan; plan for future growth and
street system/evaluate site plans for accordance with
long range plan,
(5) provide for highway appurtenances to help direct traffic
(raised medians, curbing and sidewalks),
(6) include left-turn lanes, and;
(7) install decelerate lanes.
Additional information regarding the development of access
guidelines can be found in Appendix A and B.
Given the number of accidents and findings of this report it may
suggest that additional inspection of this highway might be
warranted in the future. If additional inspection is warranted,
it may justify additional traffic engineering studies to determine
if corrective steps are needed. Potential concepts to explore
are:
• Community Awareness Programs
• Access management
• Driveway guidelines
• Signalization/intersection improvements
• Curb, sidewalks, street lights
• Animal control enforcement
• R-O-W fence modifications
Many accidents are caused by operator error and in some cases
substance abuse. Design-related changes to the roadway will
probably not prevent these type of accidents.
As a prelude to the development of this report, intergovernmental
agency meetings were held to discuss joint highway issues between
state and tribal transportation officials. The subject of accident
reports was an issue discussed. Consensus was reached between
state and tribal officials that some accidents may go unreported;
41
furthermore, the inaccurate reporting of accidents could result in
insufficient statistical documentation. In conclusion consensus
was also reached to improve training for accident investigators
and to improve accident reporting procedures with ADOT.
During the course of accessing the historical accident database
for this corridor study, several difficulties were encountered by
this group of researchers. We recorded the following observa­tions:
Accident data tends to be reported either inaccurately or
with portions of data missing. Also, the reporting process tends
to be sporadic with accident reports reaching ADOT late. In
addition, Traffic Records Unit believes the reporting of accidents
has recently decreased. This lack of precision in data collection
and reporting may create difficulty in detecting potential
hazards.
consultations were conducted with Traffic Engineering Section
concerning the accuracy of data. Traffic Engineering is of the
opinion that in-depth investigation of accident reports be
completed prior to final selection of highway safety improvements.
Based on their experience, the types of problems encountered are:
1. Accidents are not properly located on the State Highway
System.
2. Accidents reported on the State Highway System are often
determined to have taken place on local roads or
driveways.
3. Not all of the accident reports are sent to ADOT.
42
POTENTIAL CORRIDOR NEEDS
The Department conducts an analysis of service, quality and
facility condition of the highway system to quantify the invest­ment
necessary to operate the system over the next ten year
planning period. The investment requirements are potential costs
and are not actual costs. Results from this analysis are useful
in establishing an aggregate picture of future corridor transpor­tation
actions and associated costs which can be evaluated and
refined with transportation engineering and implementation
programs.
The highway system analysis is based on the needs study analytic
model and the results are constrained by the reliability and
validity of the input data, by the assumptions built into the
model, and by the assumption that all other conditions remain
unchanged. The following discussion provides a conceptual
overview of this computer analytical process.
All highway links are grouped into one of five categories depend­ing
on the amount, type and purpose of travel found on each
highway. Each of the five categories has a specifically defined
set of planning design and performance standards. These planning
design and performance standards represent the ultimate level of
improvement or development which is desirable for a given highway.
They also define the condition to which pavement will be main­tained.
Please see Appendix F for definitions of the five catego­ries
and the associated planning design and performance standards.
In the corridor study area, u.s. 191, S.R. 87, and S.R. 264 are
Level of Development (LOD) 3 routes. LOD 1 routes are controlled­access
facilities, LOD 2 routes are the most important non­controlled
access routes statewide.
Routes without unique travel or service characteristics comprise
the Level of Development 3 category. Level of Development 3
routes are mainly two-lane rural routes with provisions for
passing lanes where needed. Most of the routes on the state
system are in this category. LOD 3 routes will have some major
reconstruction projects of limited length, will be on the pavement
preservation program, and will receive regular, routine mainte­nance.
ADOT's ongoing data collection efforts provide a current inventory
of system condition. For each corridor, the routes existing
condition has been analyzed to identify deficiencies as measured
against the planning design and performance standard. The identi­fied
deficiencies provide the basis for the analytic model to
identify the type of improvement projects needed to bring the
route up to the planning design and performance standards. The
analytic model then selects the appropriate remedy action given a
highway section which contains a combination of deficiencies.
Once the appropriate remedy action is assigned, the analytic model
then estimates improvement costs. Please see Appendix G for a
43
discussion on remedy actions. Exhibit 19 illustrates the cross­section
improvements identified by the analytic model (refer to
Appendix H). U.S. Route 191 has over 100 miles of cross-section
improvements identified or almost 77 percent of the corridor
length. State Route 87 has just over 44 miles of identified
improvement to the roadway cross-section and State Route 264 has a
minor amount of mileage identified.
EXHIBIT 19
ANALYTIC MODEL
POTENTIAL ROADWAY CROSS-SECTION IMPROVEMENTS
ROUTE
NUMBER
U.S. 191
S.R. 87
S.R. 264
IMPROVEMENT
TYPE
Resurface Roadway
Reconstruction
Resurface Roadway
Resurface Roadway
Resurface Roadway
Resurface Roadway
Resurface Roadway
Resurface Roadway
MILEPOSTS
11.12-37.63
51.00-51.26
51.26-72.82
74.68-103.90
108.00-130.61
346.34-346.68
361. 82-406.04
388.45-388.79
Structural deficiencies involve bridges, grade separations, and
other structure's which carry traffic or which cross the roadway.
Those structures that do not meet current design standards are
classified as functionally obsolete. Bridge sufficiency is a
composite rating based on a structure's deficiencies in relation­ship
to the structure's use, and is indicative of sUfficiency to
remain in service. ADOT rates the sUfficiency of its bridges and
other structures on a scale of 1-100. ADOT assign? priority among
structural improvements solely on the basis of sUfficiency
ratings.
Using bridge sUfficiency ratings to prioritize improvements, ADOT
channels funds toward replacing structures with the lowest
sufficiency ratings. Bridges with sufficiency ratings below 50
are considered first. Then, depending on funding, structures with
sUfficiency ratings between 50-80 receive attention. Exhibit 20
illustrates the bridge structure improvements identified by the
analytic model (refer to Appendix H). U.S. Route 191 has three
locations noted. S.R. 87 does not have any and S.R. 264 has ten
structured locations identified.
The ADOT structures database is continuously updated to provide a
current inventory and appraisal of all structures on the State
Highway System. The bridge sUfficiency ratings contained in the
database provided the means to identify deficient structures. The
assessment of improvement costs involved manipulating the informa­tion
contained in that database to determine the replacement cost
of deficient structures.
44
EXHIBIT 20
ANALYTIC MODEL
POTENTIAL STRUCTURE IMPROVEMENTS
ROUTE
NUMBER
U.S. 191
S.R. 87
S.R. 264
MILEPOST
LOCATION
69.29
96.02
102.34
None Identified
324.10
362.65
387.30
387.94
400.60
408.54
418.55
419.30
446.20
451.30
ADOT's pavement preservation program is designed to maintain the
State Highway System at established levels of pavement condition
from year-to-year. Each year every mile of the State Highway
System is surveyed for evidence of pavement deterioration. Two
measures are used to assess pavement condition: ride roughness and
the percentage of surface cracking.
In 1980, sets of pavement condition standards were established for
major categories of roadways. For a given roadway classification,
the standards set a minimum allowable percentage pf mileage with
pavement in satisfactory condition, and a maximum allowable
percentage of mileage in objectionable condition.
ADOT's Pavement Management System computer model was used to
forecast the costs needed to maintain pavement to standards in the
coming five (5) years. Results from this computer model were used
as the basis to arrive at a statewide, non-interstate annual
average cost per mile. This statewide unit cost factor was
utilized to estimate pavement preservation costs for the ten year
corridor planning period (refer to Appendix I).
To complete the picture of anticipated corridor costs, routine
maintenance activities should be considered in the estimate of
future costs. For each corridor historical routine maintenance
costs have been collected during a three year period to calculate
the average cost-per-mile. This cost data is illustrated in
Appendix J. The corridor specific annual average unit cost factor
was utilized to estimate routine maintenance costs for the ten
year corridor planning period.
45
with the delineation of system service and quality completed the
associated corridor investment requirements can be estimated.
Potential investment requirements estimated under the level of
development concept are quantified in Exhibit 21. The potential
investment requirement for the corridors of U.S. 191, S.R. 87, and
S.R. 264 is $52,937,000 during the next ten year planning period.
Improvements to the roadway on U.S. 191 are the single largest
investment by type of improvement for any corridor. On S.R. 87,
roadway improvements are the single largest investment requirement
by type of improvement. On S.R 264, routine maintenance is the
major investment requirement. U.S. 191 has a potential corridor
investment requirement of $26,642,000 or approximately 50 percent
of the grand total for all three corridors.
The amount estimated is reasonable if the planning design and
performance standards are to be met during the next ten year
planning period. Capital investment requirements have significant
impact upon system operational decisions. Aggregate actual costs
may ultimately be higher than the potential investment require­ments.
These improvement actions and associated costs are based
on transportation planning and are not based on preliminary
highway engineering. Further evaluation and refinement is neces­sary
to identify specific improvement design and its associated
cost.
EXHIBIT 21
LEVEL OF DEVELOPMENT CONCEPT
1991-2000 POTENTIAL CORRIDOR INVESTMENT REQUIREMENTS
($1,000 1988 Prices)*
IMPROVEMENT CORRIDOR
TYPE US 191 SR 87 SR 264 TOTALS
Roadway 13,237 3,408 36 16,681
Structure 1,289 -0- 1,595 2,884
Pavement
Preservation 6,294 2,925 7,456 16,675
Routine
Maintenance 5,822 1,504 9,371 16,697
TOTAL $26,642 $7,837 $18,458 $52,937
* Rounded
46
CORRIDOR SUFFICIENCY RATINGS
The ADOT Sufficiency Rating System is a tool for evaluating and
reporting information on the condition and performance of the
State Highway System. It is a composite measure of condition,
safety and service considerations for each mile of the State
Highway System. The sUfficiency rating system:
• measures the extent to which state highway segments meet
system objectives and standards; and
• assists in the project programming process by providing an
improved means of assembling the need for improving one
highway segment relative to other highway segments.
Each of the three components of the sUfficiency rating are
measured by two roadway characteristics. The condition of the
system is evaluated by Pavement Life and Pavement Rut Depth.
Accident Rate and Severity Rate are the two measurements of
safety. Service is measured by Current Daily Traffic Per Lane and
Future Daily Traffic Per Lane. Definitions of the six roadway
characteristics are as follows:
1. Pavement Life is the number of years before some remedi­al
action will be required. It is a prediction based
upon the rate of change in pavement roughness and
cracking.
2. Pavement Rut Depth measures the depth
rutting in inches. This information
available for Interstate routes only.
of
is
pavement
currently
3. Accident Rate is the number of accidents per million
vehicle miles of travel over the three most recent
years.
4. Severity Rate is a weighted accident rate in which fatal
accidents, injury accidents and property damage acci­dents
are assigned weights of three, two and one,
respectively.
5. Current Daily Traffic Per Lane is the most recent
average daily traffic count or estimate divided by the
number of roadway lanes.
6. Future Daily Traffic Per Lane is the twenty-five year
forecast of average daily traffic volume divided by the
existing number of roadway lanes.
For every mile of the State Highway System, a good, fair, and poor
rating is assigned for each of the six roadway characteristics.
47
The ratings describe how the condition and performance for anyone
roadway segment. compare with those of other roadway segments on
the state Highway System. The sufficiency ratings are relative:
good is better than fair; fair is better than poor.
The ratings are assigned using "sufficiency rating standards" for
each of the six criteria. Roadway operating and performance
characteristics are different for freeway and arterial highways.
Consequently, different sUfficiency rating standards are used for
different Levels of Development (LOD). The Level of Development
(LOD) concept orders state routes or route segments within a
hierarchical system. There are five levels to which a route or
portion of a route can be assigned, depending on its use and
function within the State Highway System. The highest LOD is LOD
I, or Interstates and Urban controlled-access facilities, while
the lowest is LOD 5, or routes that no longer serve a statewide
function.
Because the assignment of a highway to a particular level of
development is standards-based, a highway will be reassigned to
another level of development, if the function and use of that
highway changes.
Operating and performance characteristics vary between urban and
rural highways as well. As a result, the sUfficiency rating
standards used also vary for large urban areas (over 50,000
population), small urban areas (over 5,000) and rural areas.
The sUfficiency rating standards that define good, fair, and poor
ratings were selected to provide meaningful and useful informa­tion.
The rationale used to select the standards for each of the
six roadway characteristics is as follows:
Pavement Life - ADOT uses a five year programming cycle to
schedule improvement proj ects. Roadway segments with a
projected remaining pavement life of five y~ars or less are
rated poor to identify them as candidates for improvement.
Roadway segments with a remaining life of eleven years or
more are rated good.
• Pavement Rut Depth - Pavement rut depth of 1/2" or more is
considered to be an indication of a structural problem and
will require immediate action. Pavement rut depth of 1/4" or
less is considered insignificant and is rated good (this
information is currently available only for Interstate
routes) .
Accident Rate and Severity Rate These standards were
defined in such a way that a specified percentage of the
roadway mileage is placed in each rating category. The 50%
of State Highway System mileage having the lowest accident
and severity rates is rated as good. The 10% of State
Highway System mileage with the highest accident and severity
rates is rated as poor.
48
Current and Future Daily Traffic Per Lane - These standards
generally correspond to service volumes for different levels
of service. Any roadways operating at levels of service A or
B are rated good. Urban roadways operating at level of
service E and rural roadways operating at levels of service D
or E are rated poor.
In addition to the ratings for each of the six conditions and
performance characteristics, a composite or weighted average
sUfficiency rating is computed for each mile of the state Highway
System. Condition, safety and service are considered to be
equally important and are given equal weight in computing the
composite sUfficiency rating. Likewise, the two measures of
roadway safety (accident and severity rates) and the two measures
of traffic congestion (current and future daily traffic per lane)
are considered equally important and are given equal weights.
However, the two measures of condition are not considered equally
important in computing the composite sufficiency rating. For LOD
1 (Interstates), pavement life is given twice the weight of
pavement rut depth. For urban controlled-access highways in LOD 1
and all roadway segments in LOD 2 and LOD 3, information describ­ing
pavement rutting is unavailable and pavement life alone is the
sole determinant of the condition rating and is assigned a weight
equal to the combined weight of the two safety measures or the two
service measures.
One significant problem in dealing with averages is that extreme
input values, whether good or poor, can be hidden in the final
calculation. A roadway segment with a fair composite SUfficiency
rating could have poor ratings for two or three of its condition
and service characteristics. The SUfficiency Rating System
addresses this problem by computing a "deficiency factor" for each
roadway segment.
The deficiency factor ignores good and fair SUffIciency ratings
and focuses on poor ratings. It is a number that ranges from zero
to six. For a short highway section, the deficiency factor is
simply a count of the number of characteristics with a poor
SUfficiency rating. When SUfficiency ratings are desired for more
lengthy highway sections, project boundaries or entire routes, the
SUfficiency Rating System reports distance weighted average values
for all roadway characteristics and SUfficiency ratings, and for
the deficiency factor. Under any of these circumstances, the
deficiency factor can be interpreted as follows:
• a value of zero means that there are no poor SUfficiency
ratings in any of the roadway systems evaluated;
a value of six means that all six roadway characteristics
have a poor SUfficiency rating;
a value higher than zero but lower than six means that there
are poor SUfficiency ratings for some but not all of the
characteristics evaluated.
49
Using the most current (1988) data available, the number and
percentage of route miles which fall into the poor ratings
category for five of the six roadway characteristics were calcu­lated,
as were the overall sUfficiency rating and the deficiency
factor. Pavement rutting is not included since data is available
only for Interstate routes. These calculations are useful in
evaluating the performance of u.s. 191, S.R. 87, and S.R. 264.
Exhibits 23 through 36 show where the corridor routes rate as poor
for each sUfficiency rating category. Appendix K contains each
corridor rating for deficiency factors.
The following explanations are provided in an effort to prevent
misinterpretation of data presented in this document. As a result
of systemwide management parameters, the identified corridor needs
may not be of sufficient priority on a statewide basis in meeting
defined condition standards and therefore to qualify for a portion
of the limited funding available.
This report used the most current data available, which was the
year 1988, No adjustment has~been made to the percentages of good,
fair, and poor categories when roadway sections may have been
improved since the (1988) data was collected. Furthermore, no
adjustments have been made to roadway sections which are already
scheduled for improvement.
The SUfficiency Rating System is a tool to help guide planning and
programming decisions. A comparison can be made of Exhibits 22
through 35 with the areas identified for short and long range
improvements.
50
x
(")
o
POOR
<
E
,
I
I
I
I
NAVA,IOj
I
I
8
COMPOSITE SUFFICIENCIES
UTA H
8'--,. Page
§l I
Leupp
Flagstaff
~
~
8
8
0 25 50
MILES FAIR
GOOD
As seen from Exhibit 35, U. S. 191 and S. R. 87 do not have any
mileage rated poor based on the composite sUffici~ncy. The only
blemish on S. R. 264 comes from a poor rating on segment 5 near
Window Rock. Although only .63 of a mile in length, this section
did have a large number of accidents that was confirmed by
accident reports.
EXHIBIT 35
Composite SUfficiency Ratings
Good Fair Poor
u.S. 191 Miles 65.20 64.44 0.00
Percent 50.3% 49.7% 0.00%
S.R. 87 Miles 37.00 23.47 0.00
Percent 61.2% 38.8% 0.0%
S. R. 264 Miles 36.25 117.27 0.63
Percent 23.5% 76.0% 0.4%
57
TRAFFIC ANALYSIS OF CORRIDOR ROUTES
AVERAGE DAILY TRAFFIC
Average daily traffic (ADT) measures the amount of vehicles per
day that traverse a given roadway. When used in relation to the
roadway's design capacity, it is a useful tool in evaluating the
present and future ability of' a roadway to carry traffic. For
this corridor study, ADT data for U.S. 191, S.R. 87, and S.R. 264
from 1975 to 1988 is from Tra:ffic on the Arizona Highway System,
published annually by the ADOT Travel and Facilities section; this
section also has developed forecasts through 2010 for each of the
corridor routes. Historical data for U.S. 191 prior to 1980 is
not available.
EXHIBIT 36
Actual and Projected ADT
S.R. 264, U.S. 191, and S.R. 87
ADT (thousands)
7 .
Estimate
6
5
4
3
2
1
Projection
,...U.S.191
'-S.A. 87
1975 1980 1985 1990 1995
Year
2000 2005 2010
Sources: Estimates - Traffic on the
Arizona Highway System, 1975-1988, ADOT;
Projections - ADOT Travel and Facilities
58
u.s. 191
Exhibit 36 shows estimated and pro:jected ADT for each corridor
route in its entirety within the study area. Traffic on the
entirety of u.s. 191 in the corridor study area increased from 820
in 1980 to 1,376 in 1988. It is projected that traffic will
increase to 1,816 or nearly 32%, by the year 2010. When analyzed
by segments, Segment 2, which is north of S. R. 264, has had a
higher ADT since 1980 (see Exhibit 37). This trend is expected to
continue. Overall, traffic is and will remain much lighter on
u.S. 191 compared to S.R. 264.
EXHIBIT 37
Actual and Projected ADT
U.S. 191
ADT (thousands)
2.5 Estl.mates
2
Projections
1.5
1 r -
,"--Segment 2
'--- Segment 1
0.5
1980 1985 1990 1995
Year
2000 2005 2010
Sources: Estimates - Traffic on the
Arizona Highway System,1975-1988, ADOT;
Projections - ADOT Travel and Facilities
S.R. 87
Of the three corridor study routes, S.R. 87 carries the least
amount of traffic daily (see Exhibit 36). Although traffic has
grown steadily from 1983 to 1988, there has been considerable
oscillation in annual ADT since 1975 (see Exhibit 38). Traffic is
expected to increase by 52% by 2010, equal to approximately 400
more vehicles per day. This corridor route is proj ected to
continue carrying the least amount of traffic.
59
EXHIBIT 38
Actual and Projected ADT
S.R.87
ADT (thousands)
1.4 Estimate
1.2
0.4
0.2
Projection
I , iii Iii iii iii,
1975 1980 1985 1990 1995
Year
2000 2005 2010
S.R. 264
Source8: E8t1mate - Traffic on the
Arizona Highway System. 1975-1988, "DOT;
Projection' "DOT Travel and Facilities
In 1988, the average daily traffic (ADT) on S.R. 264 was 2,589 for
the entire route (see Exhibit 36). By the year 2010, traffic is
projected to average 6,190 for the entire route, an increase of
approximately 139 percent. Traffic on this route is by far the
greatest of the three corridor routes. In Exhibit 39, the ADT for
each of the five study segments of S.R. 264 is presented.
EXHIBIT 39
Actual and Projected ADT
S.R.264
ADT (thousands)
30 Est'Imates
25
20
15
10
Projections
1975 1980 1985 1990 1995
Year
2000 2005 2010
Source8: Estlmate8 - Traffic on the
Arizona Highway System, 1975-1988, "DOT;
Projections - "DOT Travel and Facliitiea
60
ADT is highly variable from segment to segment, reflecting the
degree of urbanization and local traffic in the area. Segments 3
and 5 by far have the highest ADT in 1988. These segments are
located in the Ganado and Window Rock areas, respectively.
Segments 1 and 2, with the lowest ADT, are long rural stretches
from Tuba city toward Ganado. By 2010, disparities in ADT between
the segments will be amplified, ranging from 4,206 in Segment 2 to
24,889 for Segment 5.
The Transportation Research Board has developed design capacity
criteria for urban fringe and rural area roadways2, which is
applicable to the corridor study area. According to this criteria,
the maximum ADT that a two lane rural highway can carry is 9,000,
and the maximum that a four-lane rural highway can carry is
18,000, to achieve at least Level of Service "c" (LOS). Level of
Service is a qualitative measure of operating conditions, ranging
from LOS "A", the best operating conditions, to LOS "F", which is
the worst. In urban fringe and rural areas, LOS "D" or lower is
usually considered unacceptable. If 'traffic volume exceeds the LOS
"C" standard without access control, motorists will probably
encounter difficulties in turning on and off the roadway, limiting
their ability to change lanes, pass, or travel at preferred speed.
Without access control, a four lane roadway likely will be needed
to carry traffic higher than 9,000 ADT to ensure satisfactory
operating conditions.
All three corridor routes are predominantly two lane rural
roadways, meeting the Transportation Research Board's design
criteria. By examining Exhibits 36-39, it is apparent that only
some segments of S.R. 264 have the potential to have traffic
exceed the 9,000 ADT standard by the year 2010. More specific­ally,
Segment 5 has exceeded the st:andard since 1986, Segment 3
could do so in 1990, while Segment 4 is projected to exceed the
standard in the year 2004.
Although the three corridor routes are predomin"antly two lane
roadways, there are some four-lane sections. U.S. 191 near Chinle,
between mileposts 73.22 to 74.31, which is equal to 1.09 miles,
has four travel lanes. S.R. 264 near Polacca between mile-posts
403.02 and 403.41 is another location that has four travel lanes.
Also on S.R. 264, a stretch of four-lane roadway exists from the
st. Michaels area, starting at milepost 472.63, to the New Mexico
state line, or milepost 476.12, a distance of 3.49 miles. By
examining Exhibit 39, it is apparent that two segments of S.R. 264
have the potential of having traffic exceed the 18,000 ADT
standard by the year 2010. Segment 5. could exceed the standard by
the year 2002, while Segment 3 may exceed the standard in the year
2008, based on current projections.
2 Highway Capacity Manual, Special Report 209,
Transportation Research Board, National Research Council,
Washington D.C., 1985, pp. 8-14.
61
LAND USE
As the principal mode of transportation for goods and people in
Arizona the highway system is the essential element that provides
accessibility to all areas of the state. Highways directly impact
their immediate environment through their effect on adjacent land
use. without an adequate highway system, it is difficult to
attract and maintain economic activity.
The function of these highway:s is to serve a substantial volume of
traffic traveling at relatively high speeds on medium to long��distance
trips. The combination of this travel demand with the
travel demand of small urban and rural communities frequently
results in development along the highway wanting direct access.
In time, the proliferation of access points to the highway reduces
travel time and safety. This degradation of the capital invest­ment
frequently results in requests to improve travel time and
safety. The available options to enhance travel time and safety
include widening the roadway, relocation of the roadway or
transportation system management (TSM) actions.
The use of TSM actions can avoid the traditional approach which
requires large sums of monE~y to improve roadway capacity and
safety. Perhaps, a less costly alternative approach to protect
the facility is by controlling highway access. Currently, Arizona
does not have an effective highway access management program.
The Arizona Constitution guarantees every owner of property
abutting on a pUblic highway access to that highway. However,
only reasonable access, not direct access, to the highway is
guaranteed to property owners. Direct access to a highway is
highly desirable to commercial interests. Property owners seeking
an encroachment permit are assured of direct access, provided
access meets local ordinances, does not pose an immediate safety
hazard, and conforms to ADOT construction standards. Without any
statewide pUblic policy regulating the impacts -- due to system
access, ADOT's ability to preserve the financial investment in the
facility is impaired.
Due to the unique status of Indian lands, ADOT encounters a
difficult environment concerning access management of it's
highway. Congress and the U. S. court system has established
Indian land as a dependent sovereign nation. Conflicts in
administrative rules and policies, and regulatory authority hamper
normal operational aspects of state routes due to the unique
sovereign status of Indian land.
Additional research is needed to accurately compare the impacts of
direct access driveways upon highway capacity, safety, and capital
investment, with the impac1:s of access control upon highway
capacity, safety, and capital investment. Furthermore, case law
research is needed on: property rights, eminent domain, direct and
reasonable access, land use and access controls. It would be most
useful if this research could result in a published report which
would facilitate pUblic debate of the issues. To ensure
62
transportation objectives are
policy to increase emphasis
transportation planning. This
use and investment decisions.
achieved, it is now U. S. DOT IS
on integrating state and local
includes efforts to coordinate land
The federal government agencies including but not limited to the
Bureau of Indian Affairs, Department: of Health and Human Services,
and Housing and Urban Development should work with ADOT to develop
policies procedures, regulations and statutes concerning access
management of state highways through Indian land. Implementation
of enhanced access management will require more emphasis from both
State and Federal Government. ADOT should work with tribal and
local governments, the private se~ctor and the legislature to
develop policies, procedures, regulations and statues concerning
access control.
SOCIO-ECONOMIC ENVIRONMENT
Three counties, Apache, coconino, and Navajo and two reservations,
the Navajo Nation and the Hopi, are within the U.S. 191, S.R. 264
and S.R. 87 study area.
The counties, reservations, and communities in proximity to the
corridor routes have been analyzed for population trends from 1980
to 2010. An analysis of past and future population trends
provides an indication of what effects population has and will
have on highway demand. Population demographic changes in the
driving age population, will affect: the number of vehicles using
highways in the corridor study area.
Population estimates from 1980 to 1988 are provided by the
Department of Economic Security, except for the reservations and
their communities. In this case, sufficient housing unit data was
not available. Thus, data for the reservations and their communi­ties
for this time period are unofficial projections provided by
the Northern Arizona Council of Governments. All projections from
1989 to 2010 are provided by the Department of Economic Security.
63
EXHIBIT 40
Population of Apache, Coconino,
and Navajo Counties
19BO-2010
Population (thousands)
160 r;:::========::;-----
Eatlmate
.• - •• - Projection
140
120 Coconino County -......,.. Navajo County
It" . .---
----------- ----------
--- ---
---
100
80 . --
-~ --
---
..-_...-­---
"APache County
60
1995 2000 2005 2010
Year
1985 1990
40 f-l---L-L--l.--+-..L-L...l---L-+---l.--L-.J._1....-1---L--L-L.-L-+-.L-....l---l..----L.-+---l-..L-.l.-...JL..-.j
1980
Source: Estimatea and Projections ­Department
of Economic Security, 2/90
Exhibit 40 shows the population estimates and projections for each
of the three counties. All three counties have experienced marked
growth from 1980 to 1988, with Coconino County, the most populous,
growing the fastest rate, a.t over 24%. Growth has also been
strong in Apache County, at nearly 22%. Navajo County has had the
slowest growth, at just under 15%. Overall, the combined popula­tion
growth for all three counties since 1980 is estimated to be
approximately 39,000. From 1988 through 2010, the average annual
growth rates for Apache and Coconino Counties is expected to
decline slightly, with the opposite true for Navajo County. All
three counties are projected to have a population over 100,000 by
the year 2010, ranging from 102,600 in Apache County to 154,400 in
Coconino County.
64
EXHIBIT 41
Population of the Navajo Nation
1980-2010
--- -.... -- - _... --- -' -
.--
Population (thousands)
160.------------------------------,
140
120
100
801-·=--­60
40
20
1980 1985 1990 1995
Year
2000 2005 2010
-- 1980-1989 Projection .. --- 1990-2010 Projection
Sources: 1980-1989 Projections - NACOG;
1990-2010 Projections - Department of
Economic Security, February 1990
Exhibits 41 and 42 show the population growth of the Navajo Nation
and the Hope Reservation. From 1980 to 1988 the Navajo Nation has
seen rapid growth, at over 26%, a 2.9% average annual rate of
growth (see Exhibit 41). It is projected that nearly 50, 000
additional persons will reside in the Navajo Nation by 2010.
65
EXHIBIT 42
Population at Hopi Reservation
1980-2010
Population (thousands)
10,--------------'---------------_-.- ---, .......-... _. ..-......
8
6
4
2
-.,- ... ---
... _...... ... ... ....
1980 1985 1990 1995
Year
2000 2005 2010
-- 1980-1989 Projection ----- 1990-2010 Projection
Source.: 1980-'1989 ProJection. - NACOO;
1990-2010 ProJection. - Department of
Economic Security. February 1990
In contrast to the Navajo Nation, the Hopi Reservation has had
negligible growth from 1980 to 1988 (see Exhibit 42). However, it
is projected that the reservation will grow by over 40% from 1988
to 2010 to a population of 9,700, representing an average annual
growth rate of 1.6%.
66
The population trends of seven communities along or near the
corridor routes are shown in Exhibits 43-49. These communities
are in proximity to the corridor routes as follows:
S.R. 264 - Fort Defiance, Window Rock, and Tuba city
U.S. 191 - Chinle and Many Fanns
S.R. 87 - Dilkon and Winslow
While there are many other communi1:ies that are affected by the
corridor routes, only these communities have population data
available from the Department of Economic Security.
EXHIBIT 43
Population of Fort Defiance
1980·-2010
.. - 6
4
2
Population (thousands)
8,------------------
1980 1985 1990 19~~5
Year
2000 2005 2010
-- 1980-1989 Projection .- .. - 1990-2010 Projection
Sources: 1980-1989 ProJecltlon. - NACOG;
1990-2010 ProJection. - Department of
Economic Securltlf. February 1990
67
Exhibits 43-45 include the three communities in proximity to S.R.
264. Fort Defiance has grown by over 25% from 1980 to 1988 (see
Exhibit 43). Rapid growth is expected to continue at an unabated
pace through the year 2010, whE~n the community is proj ected to
have a population approaching 7,400.
EXHIBIT 44
Population of Window Rock
19BO-2010
Population (thousands)
5,---------------
4 ..'
.' -
3
2
1
1980 1985 1990 1~~95
'Year
2000 2005 2010
-- 1980-1989 Projection --- -- 1990-2010 Projection
Source.: 1980-1989 ProJection. - NACOG;
1990-2010 Prc)Jection. - Department of
Economic Siecurlty. February 1990
Near Ft. Defiance is the Navajo Tribal Headquarters of Window Rock
(see Exhibit 44). Window Rock has had and is projected to have
similar growth rates as its neighbor, and have a population of
over 4,800 to 2010. Indeed, thE~se two communities are expected to
be the fastest growing of the seven.
68
EXHIBIT 45
Population of "Tuba City
1980-,2010
Population (thousands)
12,----------------
10
8
6
4
2
-' '* ..
~--
---
1980 1985 1990 1995
Yea,r
2000 2005 2010
-- 1980-1989 Projection ---"'- 1990-2010 Projection
Source.: 1980-1989 Pr,oJectiona - NACOG;
1990-2010 ProJectionl. - Department of
Economic Security" February 1990
Tuba city rests at the opposite end of S.R. 264 (see Exhibit
It is the largest of the communities on the reservation,
should remain so by the year 2010, nearing 10,000 persons at
time.
69
45) .
and
that
EXHIBIT 46
Population of Chinle
19180-2010
Population (thousands)
6.--------------
5 .-.- --
4
2
1
-" --
1980 1985 1990 1!~95
'Year
2000 2005 2010
-- 1980-1989 Projection - ---- 1990-2010 Projection
Sourcu: 1980-1989 ProJection. - NACOG;
1990-2010 ProJection. - Department of
Economic S.ecurlty. February 1990
Exhibits 46 and 47 include the~ two communities in proximity to
U.S. 191. Chinle has grown at an average annual rate of 2.5% from
1980 to 1988, and is projected to grow at a slightly lower rate,
2.1%, through 2010 (see Exhibit 46).
70
EXHIBIT 47
Population of Many Farms
1980-·2010
Population (thousands)
3.--------------
2.5 .--
2
1.5 L-----
1
0.5
--- ~ -,",..,.- ---" -.-
1980 1985 1990 2000 2005 2010
- 1980-1989 Projection ----- 1990-2010 Projection
Sources: 1980-1989 Pl'oJection. - NACOG;
1990-2010 ProJection. - [)epartment of
Economic Security, Fet,ruary 1990
Many Farms, north of Chinle, has grown by nearly 19% from 1980 to
1988 (see Exhibit 47). It is projected to increase by one-half
from 1988 to 2010, to over 2,400 people.
71
EXHIBIT 48
Population of Dilkon
1980-2010
Population (thousands)
1.6...---------------
----
1.2
-~ --
---"- ---
0.8
1985 1990 2010
f--'---l.--'--------'--!---'--.l.-....L---'----t----'---'---'-,.-l--t-I--,-1--'---'---.11--+1_1,--,---,--,-1--+1------,-1-1-.L-.....L..I_1
19195 2000 2005
Year
1980
0.4
-- 1980-1989 Projection ----- 1990-2010 Projection
Sources: 1980-11989 Projections - NACOG;
1990-2010 ProHections - Department of
Economic S,ocurlty. February 1990
Exhibits 48-49 include the two communities in proximity to S.R.
87. Dilkon is the smallest of the seven communities but has grown
at the fastest average annual rate from 1980 to 1988, exceeding 7%
(see Exhibit 48). Rapid growth in Dilkon is projected to continue
through the year 2010, to 1,450 people.
72
EXHIBIT 49
Population of Winslow
1980-·2010
Population (thousands)
14,..---------------
12
10
8
6
4
2
.. - .-
1980 1985 1990 1995
Year
2000 2005 2010
-- Estimate --_ .. Projection
Source: Estimates and Projectlons­Department
of Economic Security, 2/90
Winslow, at the southern terminus of S .R. 87 within the study
area, is the largest community of the seven (see Exhibit 49).
From a population estimated at 10,725 in 1988, the community is
projected to grow to over 12,300 by 2010. This is equivalent to a
1.3% average annual growth rate.
73
Overall, the population of t:he counties, reservations, and
communities in the corridor study area is projected to increase by
at least one-third during the 1988 to 2010 time period. Growth in
the Window Rock and Ft. Defiance area will exceed 70%. This
urbanization could significantly affect traffic levels on S.R. 264
near the New Mexico border through 2010.
since the 1970's, national employment has grown faster than
population, and ADT has grown faster still, leading to increased
mobility. This is due to social and economic changes such as job
growth, increasing participation in the labor force by women, and
increasing disposable incomes. The suburban lifestyle has become
more prevalent, further dispersing the origin and destination of
trips. These trends have resulted in more travel. According to the
U. S. Department of Transportation, total highway travel (vehicle
miles traveled) increased 56% between 1969 and 19833
• This is
three times the growth in overall population, which increased 16%.
With the "baby boom" generation peaking and with fewer people
reaching driving age, this national mobility trend may change.
While certain socio-economic trends in the corridor study area are
unique or even contrary to 'the nation, it is unlikely that any
differences would create a future scenario that greatly diverges
from national trends. Key socio-economic trends that will play a
role in determining future 'traffic trends both in the corridor
study area and Arizona are net migration, and disposable personal
income.
The following national and state projections were developed by the
WEFA Group, ADOT's Adminisitra'tive Services Division, and the
Arizona Department of Economic Security , respectively. For the
next ten years, national personal income is expected to have an
average annual growth rate of 6.8% (refer to Exhibit 50). Arizona
is expected to have a higher rate of personal income growth over
the same time period, averaging 8.4% annually. The national
population is forecast to increase about 0.9% a!lnually for the
next ten years (refer to Exhibit 51). Arizona's p6pulation growth
is expected to be more than twice the national average, at 2.6%
annually. Much of Arizona's population growth will be the result
of positive net migration. This will stimulate economic activity
and help increase Arizona's share of national income and employ­ment
for the next ten years. These trends are likely to be valid
in the corridor study area as well, although local potential and
policies for economic development will be key influencing factors.
3 U.S. Department of Transportation, Personal Travel in the
U.S., V. 1, Washington, D.C.: 1986.
74
EXHIBIT 50
Forecast Rates of Change
in Personal Incomte, AZ vs. US
0% ~-----''-------'-----'--------'--
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
Fiscal Y4~ar
2%
4%
6%
8%
Percent Change
10%r--------------
- Arizona : I U.S. I
Source.: Admlnl.tratlve Service. Dlvl.lon, The WEFA Group,
Arizona Department of Economic :Becurlty
75
E:XHIBIT 51
Forecast Hates of Change
in Population, AZ vs. US
Percent Change
2.::.-----------.:--........-~
2%
1.5%
1%+----+-----+--~
~-_.-+-.--~
0.5%
0% '--_---"__--'-__-'-__.-L-._---l.__~____L___'__ _____J
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
Fiscal Year
I AI:izona -+- u.s.
Soure••: Admlnl.tr.tlv. 8tlrvle•• Dlvl.lon, Th. WEFA Group,
Arlzon. D.partment 01 Eeol~omle 8eeurlty
shows the average annual rates of population growth for
states, Arizona, and the corridor study area from 1989
If past national trends continue, mobility should
a faster rate than population. This should hold true
and the corridor study area as well.
Exhibit 52
the United
to 1999.
increase at
for Arizona
EXHIBIT 52
Projected Average Annual Rates of Population Growth 1989-99
U.S. - Arizona - Corridor Counties
United States
Arizona
Apache, Coconino and Navajo Counties
0.9%
2.6%
2.2%
The projected average annual growth rate in ADT for S.R. 264 is
more than double the average annual growth rate of population for
the corridor study, but it is much lower for U.s. 191 and somewhat
lower for S.R. 87 (see Exhibit 53). However, S.R. 264 is pro­jected
to carryover twice the amount of traffic as the other two
routes combined by 1999, placing it as the dominant traffic
carrier of the area. Thus, it is expected that past trends in
mobility growth will continue for the next decade and are appli­cable
to the corridor study area.
76
EXHIBIT 53
Projected Average Annual Rates of ADT Growth 1989-99
U.S. 191 - S.R. 87 - S.R. 264
U.S. 191
S.R. 87
S.R. 264
1. 0%
2.0%
4.8%
The key factors of population and personal income has a direct
impact on travel and the amount of revenue available to operate
the road system. Highway revenues consist of collections from
fuel and vehicle license taxes and motor carriers, driver license
and title fees which are imposed on the users of Arizona's
highways.
The price structure for supporting t.he road system is based on two
principles: access to the system and frequency of use. Some costs
paid by users do not vary with the frequency of travel. Examples
of these costs include registration or driver license fees which
are access fees. Frequency of service and distance of travel
costs are paid by users in thE~ form of fuel taxes and motor
carrier fees. These costs vary with the amount of user travel.
However, regardless of how the user pays, what is being purchased
is use of the facility. Therefore, to estimate route revenue we
can observe our future travel demand. ADOT pUblishes traffic data
on the highway system once a year. 'rhis report provides counts of
traffic for commercial and non-commercial categories. Forecasts
of future travel demand are made but are not published on a
regular basis.
ADOT's, Administrative Services Division produces a ten-year
forecast of the Highway User RevEmuE~ Fund (H.U.R.F.). The fiscal
year 1989 H.U.R.F. forecast was analyzed to split J;evenues between
commercial and non-commercial. ~~here are nine revenue categories
that must be assigned into the two traffic categories. These
assignments are not perfect but they are reasonable. Results of
the revenue allocation exercise are shown in the Appendix L. By
relating the total generated to 1:he use of the road system we can
estimate the purchase price of travel access. For both traffic
categories, the relevant unit of measurement is vehicle miles of
travel.
The total 1988 statewide vehicle miles of travel (VMT) is
estimated at 30 billion. VMT is forecast to grow to 50.8 billion
for the year 2000. The total VMT for 1991 to 2000 ten year period
is 413.6 billion. The commercial class is assigned 18 billion of
the total VMT. The purchase price of commercial access is
estimated at 12.68 cents per mile Cif travel. The non-commercial
purchase price is 0.92 cents per mile of travel. Applying these
(constant 1990 $) unit prices to t.he corridors' forecast travel
results in an estimate of revenue generated on each corridor over
the 1991-2000 ten year period.
77
united states route 191 is estimated to generate $12,220,000 in
constant 1990 dollars during this ten year period. state Route 87
is anticipated to yield $3, :;.43,000 during the ten year period.
state Route 264 is the highest earner with $29,754,000 forecast to
be generated. The combined constant 1990 dollars total earnings
forecast for the three corridors is $45,519,000 (refer to Appendix
M). However, the total amount is not available to ADOT. Of the
total revenue collected in 'the H.U.R.F., ADOT's allocation is
about 50 percent of the total which is estimated at $22,760,000.
Capital for highway improvements comes primarily from the state's
share of the H. U. R. F. with federal aid a secondary source of
capital. Non-interstate roadways such as these corridors are
eligible for federal government capital participation. Through
the first quarter of 1989, federal aid participation rates were
over ninety-two percent for primary and secondary route improve­ments,
and eighty percent of the cost for rehabilitation and
replacement of bridges.
Federal money is guided by numerous stipulations regarding its
use. These stipulations can be used to categorize improvement by
program funding category. Over the fiscal year 1991-1992 program
period, federal aid is estimated to account for $79.6 million of
the total statewide federal aid available for these non-interstate
funding categories. For fiscal year 1992-1993 program period, the
federal aid is unknown and cannot be estimated. This infusion of
federal aid has had a inoculative impact upon the operation of the
state highway system.
Investment under a market system uses the information contained in
price in order to channel resources to meet the most urgent needs.
The infusion of external capital may obscure necessary knowledge
that price communicates which can lead to unproductive and to
unsustainable investment. The United states Department of Trans­portation
(U.S. DOT) has recognized the need to structure federal
assistance programs so that the assistance does not encourage
unnecessary or unwise investment~. To this end, U. S. DOT Secretary
Skinner has recently published a "Statement of National Transpor­tation
Policy". At this time it is not clear what impact the
federal transportation policies will have on Arizona. The u.s.
Congress plays the key role in authorizing structural changes and
providing funds to the u.s. DOT. Congress has not yet acted on
the legislative agenda.
78
ULTIMATE DEVELOPMENT CONCEPT
The ultimate development concept :in rural areas is normally a
single roadway prism with two through-traffic lanes, full
shoulders and with passing lanes in selected locations. In urban
areas the through-traffic lanes may be expanded to four lanes with
curb and gutter. This concept would allow numerous lengthy
reconstruction projects designed ultimately to fit the maximum
standards. This is in contrast to the level of development
concept which allows limited reconstruction projects of limited
length with less than maximum planning standards. Potential
improvements, illustrated in Exhibits 54 and 55 are based on
analysis of service, quality and facility condition of corridors
in concert with the ultimate development concept. However, the
inclusion of an issue or problem in this document does not
indicate that it is of sufficient: priority on a statewide basis to
receive a portion of the limited funding available.
EXHIBIT 54
POTENTIAL SHORT RANGE HIGHWAY IMPROVEMENTS
U.s. 191
OVERLAY OR RECONSTRUCTION
Approximate Location By Milepost
24.0 to 37.6 +
51.0 to 73.0 +4
74.0 to 103.0 +
105.0 to 106.0 +
109.0 to 126.0 +
Approximate Length In Miles
13.6 ±
22.0 ±
29.0 ±
1.0±
17.0 +
82.6 ±
STRUCTURE IMPFlOVEMENTS
Approximate Location By Milepost
69.29
96.02
jstructure
Cottonwood Wash Bridge
Chinle Wash Bridge
INTERSECTION IMPROVEMENTS
• Junction U.S. 191 (South) & S.R. 264
Junction U.S. 191 (North) & S.R. 264 & Indian Route 15*
• Junction U.S. 191 & Indian Route 7 (monitor traffic)
* Some improvements have recently been completed.
·WB M.P. 62 to 73 was overlain 1989
79
EXHIBIT 54 (Continued)
POTENTIAL SHORT &IlliGE HIGHWAY IMPROVEMENTS
S. R. 87
OVERLAY OR RECONSTRUCTION
Approximate Location By Milepost~ Approximate Length In Miles
353.0 to 354.0 ±* 1 +
358.0 to 369.0 +* 11 +
388.0 to 389.0 ± 1 +
392.0 to 406.0 + 14 +
27 +
* M.P. 346 to 358 was overlain in 1989
Long range improvements were not identified
S.R. 264
OVERLAY OR RECONSTRUCTION
Approximate Location By Milenos't Approximate Length In Miles
322 to 325± 3 ±
332 to 337± 5 +
340 to 348± 8 +
420 to 430± 10 +
434 to 435± 1 +
442 to 444± 2 +
472 to 476± ---±-...±
33 +
80
EXHIBIT 54 (Continued)
POTENTIAL SHORT RANGE HIGHWAY IMPROVEMENTS
STRUCTURE IMPROVEMENTS
S.R. 264
Approximate Location By Milepost
324.10
362.65
408.54
446.20
451. 30
!structure
Moenkopi Wash Bridge
Dinnebito Wash Bridge
Jeddito Wash Bridge
Ganado Wash Bridge
Fish Wash Bridge
INTERSECTION IMPROVEMENTS
Junction S.R. 264 & U.S. 160; Signals warrant study
Junction S.R. 264 & Indian Route 6
Junction S.R. 264 & Indian Route 12 (South); Monitor
traffic for signals warrant study
Junction S. R. 264 & Indian Route 12 (North); Signal
improvements
• Please refer to corridor u.S. 191 for recommendations on
junction S.R. 264 & U.S. 191
CLIMBING LANES
Approximate Milepost Or Location
458.0
469.0
* Per AASHTO Guidelines
81
~pproximate Length In Miles
1. 0*
1. 0 *
EXHIBIT 55
POTENTIAL LONG RANGE HIGHWAY IMPROVEMENTS
U.S. 191
OVERLAY OR R.ECONSTRUCTION
Approximate Location By Milepost,
15.5 to 23.0 +
Approximate Length In Miles
7.5 +
WIDEN
Approximate Location By Milepost~
11. 3 +
23.0 +
Approximate Length In Miles
4.2 +
1.0+
STRUCTURE IMPROVEMENTS
Approximate Location By Milepost
102.34
Structure
Agua Sal Bridge South
Approximate Location
By Milepost
0.5 +
18.0 +
23.0 +
37.6 +
43.6 +
72.0 +
87.7 +
104.3 +
73.0 +
96.0 +
OTHER IMPROVEMENTS
Approximate Length
In Miles
4,.0 +
2.0 +
2.0 +
1.0+
1.0+
4.0 +
4.0 ±
2.0 +
1.2+
18.0 +
82
Type of Work
Fencing
Fencing
Fencing
Fencing
Fencing
Fencing
Fencing
Fencing
Sidewalks, Street
Lighting, Access
Control
Management Plan,
Driveway
Management
Plan, Community
Awareness Program
Flatten Slopes
EXHIBIT 55(continued)
POTENTIAL LONG RANGE HIGHWAY IMPROVEMENTS
S.R. 264
OVERLAY OR RECONSTRUCTION
Approximate Location By Milepost
354 to 355 +
359 to 368 +
369 to 379 +
381 to 387 +
393 to 417.5 +
Approximate Length In Miles
1 +
9 ±
10 +
6 ±
24.5+
50.5±
STRUCTURE IMPROVEMENTS
Approximate Location By Milepost
387.30
387.94
400.00
418.55
419.30
;structure
8 - 3 X 57
3 - 10 X 8
3 - 12 X 10
5 - 4 X 60
3 - 5 X 71
78
39
WIlDEN
Begin Milepost or Location
458.0 +
469.0 +
Begin Milepost or Location
446.0 +
471. 6 +
:1\pproximate Length In Miles
1.0+
1.0+
WIDEN-UHBAN/RURAL
,1\pproximate Length In Miles
2.5 +
1.0+
CLIl'1BING LANES
Approximate Milepost or Location
370.0 +
381. 0
418.0
* Per AASHTO Guidelines
83
Approximate Length In Miles
1.6+
3.2 +
1. 0* Minimum
EXHIBIT 55 (continued)
POTENTIAL LONG RANGE HIGHWAY IMPROVEMENTS
S.R. 264
OTHER IMPROVEMENTS
Approximate Location
By Milepost
Approxi.mate Length
In Miles Type of Work
403.0 + 2:.0 + Fencing
426.0 ± 2.0 + Fencing
441. 0 + 6.0 + Fencing
455.0 ± 3.0 ± Fencing
472.0 + 1.0 + Fencing
322.0 ± 3.0 + Flatten Slopes
410.0 + ~~ . 0 + Flatten Slopes
471. 6 + 4.5 ± Sidewalks,
Street Lighting,
Access Control-
Management Plan,
Driveway Manage-ment
Plan,
Community Aware-ness
Program.
84
with the delineation of short and long range potential
improvements completed, the associated corridor investment
requirements can be estimated. This is in complement to the level
of development roadway improvements identified by the analytic
computer model. The ultimate development concept investment is
quantified in Exhibit 56. The ult,ima.te development concept roadway
investment requirements for all ·thr,ee corridors is $40,597,000 to
implement the short and long range findings. This cost was
calculated using 1988 price llevels and reflects the minimum
investment requirements. Excluded from the cost estimate are costs
for reconstruction of roadways and intersection improvements and
rights of way. The estimate includes costs for resurface; if
engineering evaluation of specific roadway proves reconstruction
is needed then, significant cost increases of $1.8 million per
mile minimum can be anticipated. For future analysis purposes, a
listing of factors by year used to estimate future price levels
can be found at Appendix K.
EXHIBIT 56
ULTIMATE DEVELOPM:ENT CONCEPT
SHORT AND LONG RANGE POTENTIAL CORlHDOR INVESTMENT REQUIREMENTS
($1,000 1988 Prices)*
IMPROVEMENT ~::ORRIDOR
~
U.S.191 S .!L-~37 S.R. 264 TOTALS
Roadway 15,956 3,942 20,699 40,597**
Structure 1,289 -()- 1,595 2,884
Pavement
Preservation 6,294 2,925 7,456 16,675
Routine
Maintenance 5,822 1,504 9,371 16,697
TOTAL 29,361 8,371 39,121 76,853
* Rounded.
** See Appendix 0 for comparison explanation.
Sources and Assumptions: Roadway-Cost based on Manual of Highway
Improvement and Maintenance Cost" .January, 1989. Excludes costs
for reconstruction of roadway, intersection improvements and
rights-of-way. Structure/Pavement Preservation/Routine
Maintenance-Costs based on 1990 Need Study (potential corridor
investment requirements-analytic :model), pavement preservation and
routine maintenance as identified in appendices I and J.
8:5
Finding sufficient financial rE~sources to implement potential
improvements presents a herculean effort to ADOT's managers. Are
the efforts of managers of ADOT in danger of being undermined by a
pUblic that continues to focus on desires and not what is
affordable, and in this process implement projects that increase
the states burdens with the ensuing economic consequences? It is
important to emphasize the 40.6 million dollar roadway-only
improvement investment is the~ minimum amount required under the
ultimate development concept. Given the lack of precision in the
cost manual and the un-quantified mileage for reconstruction
projects, this number is believed to be low. In addition, based
upon experience, this figurE~ i.s likely to be underestimated.
However, the amount is useful for financial analysis purposes if
it is clearly understood, actual costs are likely to be higher.
This raises a systemwide quest.ion: Should users of a facility pay
for benefits received?
86
APPENDIX A
LOCAL GOVERNMENT
GUIDELINES FOR DRIVEWAYS
It is desirable for the Chapte~r Houses and Tribal Council to
develop driveway and access guidlelines for all new development as
well as redevelopment of existing areas. The following is a
suggested draft set of driveway guidelines that could be applied.
These guidelines or a modified version should greatly reduce the
proliferation of driveway along sta'te highways and improve access
control. They should be incorporatled into existing Chapter House
Ordinances where not now included.
1. No driveway onto an arterial street or collector street
shall be located closler than 100 feet to the nearest
intersecting curb line.
2. One driveway will be permitted when the frontage is less
than 300 feet. Two drivev;rays will be permitted when the
frontage is 300 feet or greater.
3. Adjacent driveways should be no closer than 60 feet.
4. The use of shared drivevlays between adj acent parcels
should be encouraged whenlever possible.
5. Driveways on opposite sides of a street should not be
offset less than 150 feet.
6. A main driveway into a si.te should not -have any inter­sections
with parking aisles or on-site streets within
80 feet of the arterial street curb line.
7. No driveway within 100 fe:et of a median opening unless
it is directly opposite the opening.
The contents in this appendix do not necessarily reflect the
official policies of the STATE. This appendix does not constitute
a standard, specification, or regulation. In this regard, ADOT
has currently undertaken research on the issue of access
management and access management plans.
87
APPENDIX B
DRIVEWAYS AND ACCESS MANAGEMENT REFERENCES
Development of local ordinances and documents will be aided by
reviewing prominent reference pUblications. The following
publications should prove useful for transportation planning
standards.
Guidelines for Driveway Design and Location; ITE, 1974
Guidelines for Planning and Designing Access Systems for
Shopping Centers; ITE, 1975
• Guidelines for Control of Direct Access to Arterial
Highways; FHWA, 1975
Guidelines for Medial and Marginal Access Control on
Major Roadways; NCHRP, 1970
A Policy on Geometric Design of Highways and Streets;
AASHTO, 1984
• Guidelines for Urban l~ajor street Design; Institute of
Transportation Engineers (ITE) , 1984
Traffic Engineering Handbook; Institute of Transporta­tion
Engineers, 1984
• Manual on Uniform Traffic Control Devices; Federal
Highway Administration (FHWA), 1984
Transportation and Traffic Engineering Handbook, 2nd
Edition
Trip Generation Handbook, ITE, Current !dition
Transportation Research Board; Circular 212
Highway Capacity Mamu2lI, 1965; National Research Council
National Cooperative Highway Research Program, Report
186
•
•
•
•
National Cooperative Highway Research Program, Report
187
Highway capacity Manual, TRB Special Report 209
site Impact Traffic Evaluation, ITE
Traffic Impact Analysis, APA, PAS Report No. 387
state Highway Sy~tem Plan, ADOT, September, 1990,
Phoenix, AZ
88
APPENDIX C
Reported Accidemts on U.S. 191
1986 1987 1988 1989 Total ~
...2-
Segment 1 20 24 21 9 74 20.5
Segment 2 94 91 49 53 287 79.5
Totals 114 115 70 62 361 100.0
Injuries and Fatalities on U.S. 191
Injuries Fat:al;ities Total
Segment 1 54 5 59
Segment 2 148 9 157
Total 202 14
Accident By Type For U.S. 191
1986 1987 1988 1989 Total ~
...2-
Hit Animals 30 27 25 8 90 25.0
Ran-off
Roadway 31 9 15 17 72 20.0
Rear-end 9 16 9 5 39 11. 0
Overturned
In Road 2 20 8 2 32 9.0
Turning Left 8 3 3 9 23 6.0
Other 34 40 10 21 105 29.0
Total 114 115 70 62 361 100.0
89
Drivers' Physic§l Condition on U.S. 191
1986 1987 1988 1989 Total ~
.2-
No Apparent
Defects 113 107 65 63 348 70.7
Unknown 16 19 9 7 51 10.4
Alcohol
Related 20 30 15, 8 73 14.8
Sleepy/Fatigue
& Other 8 3 2: 7 20 4.0
Total 157 159 91 85 492* 100.0
* NOTE: Figures reported in the "total column differ from figures
reported for total acciden1:s. This is due to reporting
of physical condition for each driver in two vehicle
accidents.
90
APPENDIX D
Reported Accidents on S.R. 87
Segment 1 9 15 18 9
Total
51 100.0
Injuries and Fatalities on S.R. 87
Segment 1
Injuries
Fatalities
8
o
19
1
8
3
21
o
Total
56
4
100.0
100.0
Accident Types For S.R. 87
Ran-off
Roadway
Overturned
In Road
Hit Fixed
Object
Other
Total
7
o
1
1
9
3
4
2
6
15
2
7
2
7
18
3
1
1
4
9
Total
15
12
6
18
51
29.4
23.5
11. 8
35.3
100.0
Drivers' Physical Condition on S.R. ~7
No Apparent
Defects 1
Unknown 2
Alcohol
Related 2
Sleepy/Fatigue
& Other 4
7
4
5
2
12
7
3
1
4
5
3
1
Total
24
18
13
8
38.1
28.6
20.6
12.7
Total
* NOTE:
9 18 23 13 63* 100.0
Figures reported in the total column differ from figures
reported for total accidents. This is due to reporting
of physical condition of each driver in two vehicle
accidents.
91
APPENDIX E
Reported AccidE~nts on S.R. 264
1986 1987 1988 1989 Total ~
...2.
Segment 1 11 11 34 34 90 17.8
Segment 2 35 31 40 34 140 27.8
Segment 3 4 3 6 2 15 3.0
Segment 4 38 39 3 -ret.. 21 130 25.7
Segment 5 36 35 36 23 130 25.7
Total 124 119 148 114 505 100.0
Injuries and Fatalities on S.R. 264
1986 1987 1988 1989 Total ~
...2.
Segment 1
Injuries 6 13 3:2 36 80 23.1
Fatalities 1 1 :3 0 5 16.1
Segment 2
Injuries 16 22 27 26 91 26.2
Fatalities 5 1 .2 0 8 25.8
Segment 3
Injuries 2 7 4 0 13 3.7
Fatalities 0 0 0 0 0 0.0
Segment 4
Injuries 36 24 23 27 110 31.7
Fatalities 3 1 2 3 9 29.0
Segment 5
Injuries 9 15 15 7 46 13.3
Fatalities 1 1 6 1 9 29.0
Total
Injuries 69 81 101 96 347 100.0
Fatalities 10 4 13 4 31 100.0
92
Accident Types For S.R. 264
1986 1987 1988 1989 Total 9,-
...£.
Ran-off
Roadway 38 17 29 32 116 23.0
Hit Animals 24 21 25 16 86 17.0
Rear-end 15 13 21 18 67 13.3
Other 47 68 73 48 236 46.7
Total 124 119 148 114 505 100.0
Drivers' Physical Condition on S.R. 264
1986 1987 1988 1989 Total 9,-
...£.
No Apparent
Defects 114 119 151 120 504 69.6
Unknown 24 20 18 16 78 10.8
Alcohol
Related 27 26 31 24 108 14.9
sleepy/Fatigue
& Other 10 7 11 6 34 4.7
Total 175 172 211 166 724* 100.0
* NOTE: Figures reported in the total column differ from figures
reported for total accidents. This is due to reporting
of physical condition of each driver in two vehicle
accidents.
93
APPENDIX F
LEVEL OF DEVELOPMENT
Central to the ADOT assessment of System needs is the notion of
Level of Development, a planni.ng tool introduced as an integrative
concept in the recent StatE~ Highway System Plan. Level of
Development provides a hierarchical ordering of System routes into
five categories in terms of t:he relative importance of routes to
the System as a whole. The assignment to a Level of Development
category takes into consi.deration the route's functional
classification, level of significance, current and future daily
traffic, current and future truck traffic, and other unique route
characteristics (e.g., recreational use). The five levels of
development are described below.
Level of Development 1: IntE~rsitate and urban controlled-access
facilities form the backbone of the System. Among many functions
served, Level of Development 1 routes provide the principal means
of interstate travel, serve t,he greatest volume of traffic, link
the state's metropolitan areas, and provide the major truck
routes. These routes are built and maintained to the highest
standards.
Level of Development 2: In tE~rms of both use and function, Level
of Development 2 routes are the most important non-controlled
access routes statewide. For the most part, these routes were
constructed as two-l